mirror of https://github.com/emirpasic/gods
Emir Pasic
7 years ago
committed by
GitHub
commit
f2025ad180
@ -0,0 +1,50 @@
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// Copyright (c) 2015, Emir Pasic. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package examples
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import (
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"fmt"
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avl "github.com/emirpasic/gods/trees/avltree"
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)
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// AVLTreeExample to demonstrate basic usage of AVLTree
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func AVLTreeExample() {
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tree := avl.NewWithIntComparator() // empty(keys are of type int)
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tree.Put(1, "x") // 1->x
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tree.Put(2, "b") // 1->x, 2->b (in order)
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tree.Put(1, "a") // 1->a, 2->b (in order, replacement)
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tree.Put(3, "c") // 1->a, 2->b, 3->c (in order)
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tree.Put(4, "d") // 1->a, 2->b, 3->c, 4->d (in order)
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tree.Put(5, "e") // 1->a, 2->b, 3->c, 4->d, 5->e (in order)
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tree.Put(6, "f") // 1->a, 2->b, 3->c, 4->d, 5->e, 6->f (in order)
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fmt.Println(tree)
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//
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// AVLTree
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// │ ┌── 6
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// │ ┌── 5
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// └── 4
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// │ ┌── 3
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// └── 2
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// └── 1
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_ = tree.Values() // []interface {}{"a", "b", "c", "d", "e", "f"} (in order)
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_ = tree.Keys() // []interface {}{1, 2, 3, 4, 5, 6} (in order)
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tree.Remove(2) // 1->a, 3->c, 4->d, 5->e, 6->f (in order)
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fmt.Println(tree)
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//
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// AVLTree
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// │ ┌── 6
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// │ ┌── 5
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// └── 4
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// └── 3
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// └── 1
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tree.Clear() // empty
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tree.Empty() // true
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tree.Size() // 0
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}
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@ -0,0 +1,449 @@
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// Copyright (c) 2017, Benjamin Scher Purcell. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package avltree implements an AVL balanced binary tree.
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//
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// Structure is not thread safe.
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//
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// References: https://en.wikipedia.org/wiki/AVL_tree
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package avltree
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import (
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"fmt"
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"github.com/emirpasic/gods/trees"
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"github.com/emirpasic/gods/utils"
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)
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func assertTreeImplementation() {
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var _ trees.Tree = new(Tree)
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}
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// Tree holds elements of the AVL tree.
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type Tree struct {
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Root *Node // Root node
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Comparator utils.Comparator // Key comparator
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size int // Total number of keys in the tree
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}
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// Node is a single element within the tree
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type Node struct {
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Key interface{}
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Value interface{}
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Parent *Node // Parent node
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Children [2]*Node // Children nodes
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b int8
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}
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// NewWith instantiates an AVL tree with the custom comparator.
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func NewWith(comparator utils.Comparator) *Tree {
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return &Tree{Comparator: comparator}
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}
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// NewWithIntComparator instantiates an AVL tree with the IntComparator, i.e. keys are of type int.
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func NewWithIntComparator() *Tree {
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return &Tree{Comparator: utils.IntComparator}
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}
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// NewWithStringComparator instantiates an AVL tree with the StringComparator, i.e. keys are of type string.
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func NewWithStringComparator() *Tree {
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return &Tree{Comparator: utils.StringComparator}
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}
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// Put inserts node into the tree.
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// Key should adhere to the comparator's type assertion, otherwise method panics.
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func (t *Tree) Put(key interface{}, value interface{}) {
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t.put(key, value, nil, &t.Root)
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}
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// Get searches the node in the tree by key and returns its value or nil if key is not found in tree.
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// Second return parameter is true if key was found, otherwise false.
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// Key should adhere to the comparator's type assertion, otherwise method panics.
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func (t *Tree) Get(key interface{}) (value interface{}, found bool) {
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n := t.Root
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for n != nil {
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cmp := t.Comparator(key, n.Key)
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switch {
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case cmp == 0:
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return n.Value, true
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case cmp < 0:
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n = n.Children[0]
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case cmp > 0:
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n = n.Children[1]
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}
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}
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return nil, false
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}
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// Remove remove the node from the tree by key.
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// Key should adhere to the comparator's type assertion, otherwise method panics.
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func (t *Tree) Remove(key interface{}) {
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t.remove(key, &t.Root)
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}
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// Empty returns true if tree does not contain any nodes.
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func (t *Tree) Empty() bool {
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return t.size == 0
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}
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// Size returns the number of elements stored in the tree.
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func (t *Tree) Size() int {
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return t.size
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}
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// Keys returns all keys in-order
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func (t *Tree) Keys() []interface{} {
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keys := make([]interface{}, t.size)
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it := t.Iterator()
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for i := 0; it.Next(); i++ {
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keys[i] = it.Key()
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}
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return keys
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}
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// Values returns all values in-order based on the key.
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func (t *Tree) Values() []interface{} {
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values := make([]interface{}, t.size)
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it := t.Iterator()
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for i := 0; it.Next(); i++ {
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values[i] = it.Value()
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}
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return values
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}
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// Left returns the minimum element of the AVL tree
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// or nil if the tree is empty.
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func (t *Tree) Left() *Node {
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return t.bottom(0)
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}
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// Right returns the maximum element of the AVL tree
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// or nil if the tree is empty.
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func (t *Tree) Right() *Node {
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return t.bottom(1)
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}
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// Floor Finds floor node of the input key, return the floor node or nil if no ceiling is found.
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// Second return parameter is true if floor was found, otherwise false.
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//
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// Floor node is defined as the largest node that is smaller than or equal to the given node.
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// A floor node may not be found, either because the tree is empty, or because
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// all nodes in the tree is larger than the given node.
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//
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// Key should adhere to the comparator's type assertion, otherwise method panics.
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func (t *Tree) Floor(key interface{}) (floor *Node, found bool) {
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found = false
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n := t.Root
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for n != nil {
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c := t.Comparator(key, n.Key)
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switch {
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case c == 0:
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return n, true
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case c < 0:
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n = n.Children[0]
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case c > 0:
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floor, found = n, true
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n = n.Children[1]
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}
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}
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if found {
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return
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}
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return nil, false
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}
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// Ceiling finds ceiling node of the input key, return the ceiling node or nil if no ceiling is found.
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// Second return parameter is true if ceiling was found, otherwise false.
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//
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// Ceiling node is defined as the smallest node that is larger than or equal to the given node.
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// A ceiling node may not be found, either because the tree is empty, or because
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// all nodes in the tree is smaller than the given node.
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//
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// Key should adhere to the comparator's type assertion, otherwise method panics.
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func (t *Tree) Ceiling(key interface{}) (floor *Node, found bool) {
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found = false
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n := t.Root
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for n != nil {
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c := t.Comparator(key, n.Key)
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switch {
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case c == 0:
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return n, true
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case c < 0:
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floor, found = n, true
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n = n.Children[0]
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case c > 0:
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n = n.Children[1]
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}
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}
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if found {
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return
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}
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return nil, false
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}
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// Clear removes all nodes from the tree.
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func (t *Tree) Clear() {
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t.Root = nil
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t.size = 0
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}
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// String returns a string representation of container
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func (t *Tree) String() string {
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str := "AVLTree\n"
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if !t.Empty() {
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output(t.Root, "", true, &str)
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}
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return str
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}
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func (n *Node) String() string {
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return fmt.Sprintf("%v", n.Key)
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}
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func (t *Tree) put(key interface{}, value interface{}, p *Node, qp **Node) bool {
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q := *qp
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if q == nil {
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t.size++
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*qp = &Node{Key: key, Value: value, Parent: p}
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return true
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}
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c := t.Comparator(key, q.Key)
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if c == 0 {
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q.Key = key
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q.Value = value
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return false
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}
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if c < 0 {
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c = -1
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} else {
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c = 1
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}
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a := (c + 1) / 2
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var fix bool
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fix = t.put(key, value, q, &q.Children[a])
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if fix {
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return putFix(int8(c), qp)
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}
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return false
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}
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func (t *Tree) remove(key interface{}, qp **Node) bool {
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q := *qp
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if q == nil {
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return false
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}
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c := t.Comparator(key, q.Key)
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if c == 0 {
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t.size--
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if q.Children[1] == nil {
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if q.Children[0] != nil {
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q.Children[0].Parent = q.Parent
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}
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*qp = q.Children[0]
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return true
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}
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fix := removeMin(&q.Children[1], &q.Key, &q.Value)
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if fix {
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return removeFix(-1, qp)
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}
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return false
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}
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if c < 0 {
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c = -1
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} else {
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c = 1
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}
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a := (c + 1) / 2
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fix := t.remove(key, &q.Children[a])
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if fix {
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return removeFix(int8(-c), qp)
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}
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return false
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}
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func removeMin(qp **Node, minKey *interface{}, minVal *interface{}) bool {
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q := *qp
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if q.Children[0] == nil {
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*minKey = q.Key
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*minVal = q.Value
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if q.Children[1] != nil {
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q.Children[1].Parent = q.Parent
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}
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*qp = q.Children[1]
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return true
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}
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fix := removeMin(&q.Children[0], minKey, minVal)
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if fix {
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return removeFix(1, qp)
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}
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return false
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}
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func putFix(c int8, t **Node) bool {
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s := *t
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if s.b == 0 {
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s.b = c
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return true
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}
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if s.b == -c {
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s.b = 0
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return false
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}
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if s.Children[(c+1)/2].b == c {
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s = singlerot(c, s)
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} else {
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s = doublerot(c, s)
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}
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*t = s
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return false
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}
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func removeFix(c int8, t **Node) bool {
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s := *t
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if s.b == 0 {
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s.b = c
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return false
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}
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if s.b == -c {
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s.b = 0
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return true
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}
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a := (c + 1) / 2
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if s.Children[a].b == 0 {
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s = rotate(c, s)
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s.b = -c
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*t = s
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return false
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}
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if s.Children[a].b == c {
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s = singlerot(c, s)
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} else {
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s = doublerot(c, s)
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}
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*t = s
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return true
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}
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func singlerot(c int8, s *Node) *Node {
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s.b = 0
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s = rotate(c, s)
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s.b = 0
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return s
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}
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func doublerot(c int8, s *Node) *Node {
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a := (c + 1) / 2
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r := s.Children[a]
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s.Children[a] = rotate(-c, s.Children[a])
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p := rotate(c, s)
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switch {
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default:
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s.b = 0
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r.b = 0
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case p.b == c:
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s.b = -c
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r.b = 0
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case p.b == -c:
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s.b = 0
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r.b = c
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}
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p.b = 0
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return p
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}
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func rotate(c int8, s *Node) *Node {
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a := (c + 1) / 2
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r := s.Children[a]
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s.Children[a] = r.Children[a^1]
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if s.Children[a] != nil {
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s.Children[a].Parent = s
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}
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r.Children[a^1] = s
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r.Parent = s.Parent
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s.Parent = r
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return r
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}
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func (t *Tree) bottom(d int) *Node {
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n := t.Root
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if n == nil {
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return nil
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}
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for c := n.Children[d]; c != nil; c = n.Children[d] {
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n = c
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}
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return n
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}
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// Prev returns the previous element in an inorder
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// walk of the AVL tree.
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func (n *Node) Prev() *Node {
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return n.walk1(0)
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}
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// Next returns the next element in an inorder
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// walk of the AVL tree.
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func (n *Node) Next() *Node {
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return n.walk1(1)
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}
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func (n *Node) walk1(a int) *Node {
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if n == nil {
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return nil
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}
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if n.Children[a] != nil {
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n = n.Children[a]
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for n.Children[a^1] != nil {
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n = n.Children[a^1]
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}
|
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return n
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}
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|
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p := n.Parent
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for p != nil && p.Children[a] == n {
|
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n = p
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p = p.Parent
|
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}
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return p
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}
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func output(node *Node, prefix string, isTail bool, str *string) {
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if node.Children[1] != nil {
|
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newPrefix := prefix
|
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if isTail {
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newPrefix += "│ "
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} else {
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newPrefix += " "
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}
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output(node.Children[1], newPrefix, false, str)
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}
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*str += prefix
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if isTail {
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*str += "└── "
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} else {
|
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*str += "┌── "
|
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}
|
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*str += node.String() + "\n"
|
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if node.Children[0] != nil {
|
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newPrefix := prefix
|
||||
if isTail {
|
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newPrefix += " "
|
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} else {
|
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newPrefix += "│ "
|
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}
|
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output(node.Children[0], newPrefix, true, str)
|
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}
|
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}
|
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@ -0,0 +1,710 @@
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package avltree
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"testing"
|
||||
)
|
||||
|
||||
func TestAVLTreePut(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(5, "e")
|
||||
tree.Put(6, "f")
|
||||
tree.Put(7, "g")
|
||||
tree.Put(3, "c")
|
||||
tree.Put(4, "d")
|
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tree.Put(1, "x")
|
||||
tree.Put(2, "b")
|
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tree.Put(1, "a") //overwrite
|
||||
|
||||
if actualValue := tree.Size(); actualValue != 7 {
|
||||
t.Errorf("Got %v expected %v", actualValue, 7)
|
||||
}
|
||||
if actualValue, expectedValue := fmt.Sprintf("%d%d%d%d%d%d%d", tree.Keys()...), "1234567"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if actualValue, expectedValue := fmt.Sprintf("%s%s%s%s%s%s%s", tree.Values()...), "abcdefg"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
|
||||
tests1 := [][]interface{}{
|
||||
{1, "a", true},
|
||||
{2, "b", true},
|
||||
{3, "c", true},
|
||||
{4, "d", true},
|
||||
{5, "e", true},
|
||||
{6, "f", true},
|
||||
{7, "g", true},
|
||||
{8, nil, false},
|
||||
}
|
||||
|
||||
for _, test := range tests1 {
|
||||
// retrievals
|
||||
actualValue, actualFound := tree.Get(test[0])
|
||||
if actualValue != test[1] || actualFound != test[2] {
|
||||
t.Errorf("Got %v expected %v", actualValue, test[1])
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeRemove(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(5, "e")
|
||||
tree.Put(6, "f")
|
||||
tree.Put(7, "g")
|
||||
tree.Put(3, "c")
|
||||
tree.Put(4, "d")
|
||||
tree.Put(1, "x")
|
||||
tree.Put(2, "b")
|
||||
tree.Put(1, "a") //overwrite
|
||||
|
||||
tree.Remove(5)
|
||||
tree.Remove(6)
|
||||
tree.Remove(7)
|
||||
tree.Remove(8)
|
||||
tree.Remove(5)
|
||||
|
||||
if actualValue, expectedValue := fmt.Sprintf("%d%d%d%d", tree.Keys()...), "1234"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if actualValue, expectedValue := fmt.Sprintf("%s%s%s%s", tree.Values()...), "abcd"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if actualValue, expectedValue := fmt.Sprintf("%s%s%s%s", tree.Values()...), "abcd"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if actualValue := tree.Size(); actualValue != 4 {
|
||||
t.Errorf("Got %v expected %v", actualValue, 7)
|
||||
}
|
||||
|
||||
tests2 := [][]interface{}{
|
||||
{1, "a", true},
|
||||
{2, "b", true},
|
||||
{3, "c", true},
|
||||
{4, "d", true},
|
||||
{5, nil, false},
|
||||
{6, nil, false},
|
||||
{7, nil, false},
|
||||
{8, nil, false},
|
||||
}
|
||||
|
||||
for _, test := range tests2 {
|
||||
actualValue, actualFound := tree.Get(test[0])
|
||||
if actualValue != test[1] || actualFound != test[2] {
|
||||
t.Errorf("Got %v expected %v", actualValue, test[1])
|
||||
}
|
||||
}
|
||||
|
||||
tree.Remove(1)
|
||||
tree.Remove(4)
|
||||
tree.Remove(2)
|
||||
tree.Remove(3)
|
||||
tree.Remove(2)
|
||||
tree.Remove(2)
|
||||
|
||||
if actualValue, expectedValue := fmt.Sprintf("%s", tree.Keys()), "[]"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if actualValue, expectedValue := fmt.Sprintf("%s", tree.Values()), "[]"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if empty, size := tree.Empty(), tree.Size(); empty != true || size != -0 {
|
||||
t.Errorf("Got %v expected %v", empty, true)
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
func TestAVLTreeLeftAndRight(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
|
||||
if actualValue := tree.Left(); actualValue != nil {
|
||||
t.Errorf("Got %v expected %v", actualValue, nil)
|
||||
}
|
||||
if actualValue := tree.Right(); actualValue != nil {
|
||||
t.Errorf("Got %v expected %v", actualValue, nil)
|
||||
}
|
||||
|
||||
tree.Put(1, "a")
|
||||
tree.Put(5, "e")
|
||||
tree.Put(6, "f")
|
||||
tree.Put(7, "g")
|
||||
tree.Put(3, "c")
|
||||
tree.Put(4, "d")
|
||||
tree.Put(1, "x") // overwrite
|
||||
tree.Put(2, "b")
|
||||
|
||||
if actualValue, expectedValue := fmt.Sprintf("%d", tree.Left().Key), "1"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if actualValue, expectedValue := fmt.Sprintf("%s", tree.Left().Value), "x"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
|
||||
if actualValue, expectedValue := fmt.Sprintf("%d", tree.Right().Key), "7"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if actualValue, expectedValue := fmt.Sprintf("%s", tree.Right().Value), "g"; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeCeilingAndFloor(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
|
||||
if node, found := tree.Floor(0); node != nil || found {
|
||||
t.Errorf("Got %v expected %v", node, "<nil>")
|
||||
}
|
||||
if node, found := tree.Ceiling(0); node != nil || found {
|
||||
t.Errorf("Got %v expected %v", node, "<nil>")
|
||||
}
|
||||
|
||||
tree.Put(5, "e")
|
||||
tree.Put(6, "f")
|
||||
tree.Put(7, "g")
|
||||
tree.Put(3, "c")
|
||||
tree.Put(4, "d")
|
||||
tree.Put(1, "x")
|
||||
tree.Put(2, "b")
|
||||
|
||||
if node, found := tree.Floor(4); node.Key != 4 || !found {
|
||||
t.Errorf("Got %v expected %v", node.Key, 4)
|
||||
}
|
||||
if node, found := tree.Floor(0); node != nil || found {
|
||||
t.Errorf("Got %v expected %v", node, "<nil>")
|
||||
}
|
||||
|
||||
if node, found := tree.Ceiling(4); node.Key != 4 || !found {
|
||||
t.Errorf("Got %v expected %v", node.Key, 4)
|
||||
}
|
||||
if node, found := tree.Ceiling(8); node != nil || found {
|
||||
t.Errorf("Got %v expected %v", node, "<nil>")
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIteratorNextOnEmpty(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
it := tree.Iterator()
|
||||
for it.Next() {
|
||||
t.Errorf("Shouldn't iterate on empty tree")
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIteratorPrevOnEmpty(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
it := tree.Iterator()
|
||||
for it.Prev() {
|
||||
t.Errorf("Shouldn't iterate on empty tree")
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIterator1Next(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(5, "e")
|
||||
tree.Put(6, "f")
|
||||
tree.Put(7, "g")
|
||||
tree.Put(3, "c")
|
||||
tree.Put(4, "d")
|
||||
tree.Put(1, "x")
|
||||
tree.Put(2, "b")
|
||||
tree.Put(1, "a") //overwrite
|
||||
// │ ┌── 7
|
||||
// └── 6
|
||||
// │ ┌── 5
|
||||
// └── 4
|
||||
// │ ┌── 3
|
||||
// └── 2
|
||||
// └── 1
|
||||
it := tree.Iterator()
|
||||
count := 0
|
||||
for it.Next() {
|
||||
count++
|
||||
key := it.Key()
|
||||
switch key {
|
||||
case count:
|
||||
if actualValue, expectedValue := key, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
default:
|
||||
if actualValue, expectedValue := key, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
}
|
||||
if actualValue, expectedValue := count, tree.Size(); actualValue != expectedValue {
|
||||
t.Errorf("Size different. Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIterator1Prev(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(5, "e")
|
||||
tree.Put(6, "f")
|
||||
tree.Put(7, "g")
|
||||
tree.Put(3, "c")
|
||||
tree.Put(4, "d")
|
||||
tree.Put(1, "x")
|
||||
tree.Put(2, "b")
|
||||
tree.Put(1, "a") //overwrite
|
||||
// │ ┌── 7
|
||||
// └── 6
|
||||
// │ ┌── 5
|
||||
// └── 4
|
||||
// │ ┌── 3
|
||||
// └── 2
|
||||
// └── 1
|
||||
it := tree.Iterator()
|
||||
for it.Next() {
|
||||
}
|
||||
countDown := tree.size
|
||||
for it.Prev() {
|
||||
key := it.Key()
|
||||
switch key {
|
||||
case countDown:
|
||||
if actualValue, expectedValue := key, countDown; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
default:
|
||||
if actualValue, expectedValue := key, countDown; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
countDown--
|
||||
}
|
||||
if actualValue, expectedValue := countDown, 0; actualValue != expectedValue {
|
||||
t.Errorf("Size different. Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIterator2Next(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(3, "c")
|
||||
tree.Put(1, "a")
|
||||
tree.Put(2, "b")
|
||||
it := tree.Iterator()
|
||||
count := 0
|
||||
for it.Next() {
|
||||
count++
|
||||
key := it.Key()
|
||||
switch key {
|
||||
case count:
|
||||
if actualValue, expectedValue := key, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
default:
|
||||
if actualValue, expectedValue := key, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
}
|
||||
if actualValue, expectedValue := count, tree.Size(); actualValue != expectedValue {
|
||||
t.Errorf("Size different. Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIterator2Prev(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(3, "c")
|
||||
tree.Put(1, "a")
|
||||
tree.Put(2, "b")
|
||||
it := tree.Iterator()
|
||||
for it.Next() {
|
||||
}
|
||||
countDown := tree.size
|
||||
for it.Prev() {
|
||||
key := it.Key()
|
||||
switch key {
|
||||
case countDown:
|
||||
if actualValue, expectedValue := key, countDown; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
default:
|
||||
if actualValue, expectedValue := key, countDown; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
countDown--
|
||||
}
|
||||
if actualValue, expectedValue := countDown, 0; actualValue != expectedValue {
|
||||
t.Errorf("Size different. Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIterator3Next(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(1, "a")
|
||||
it := tree.Iterator()
|
||||
count := 0
|
||||
for it.Next() {
|
||||
count++
|
||||
key := it.Key()
|
||||
switch key {
|
||||
case count:
|
||||
if actualValue, expectedValue := key, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
default:
|
||||
if actualValue, expectedValue := key, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
}
|
||||
if actualValue, expectedValue := count, tree.Size(); actualValue != expectedValue {
|
||||
t.Errorf("Size different. Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIterator3Prev(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(1, "a")
|
||||
it := tree.Iterator()
|
||||
for it.Next() {
|
||||
}
|
||||
countDown := tree.size
|
||||
for it.Prev() {
|
||||
key := it.Key()
|
||||
switch key {
|
||||
case countDown:
|
||||
if actualValue, expectedValue := key, countDown; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
default:
|
||||
if actualValue, expectedValue := key, countDown; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
countDown--
|
||||
}
|
||||
if actualValue, expectedValue := countDown, 0; actualValue != expectedValue {
|
||||
t.Errorf("Size different. Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIterator4Next(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(13, 5)
|
||||
tree.Put(8, 3)
|
||||
tree.Put(17, 7)
|
||||
tree.Put(1, 1)
|
||||
tree.Put(11, 4)
|
||||
tree.Put(15, 6)
|
||||
tree.Put(25, 9)
|
||||
tree.Put(6, 2)
|
||||
tree.Put(22, 8)
|
||||
tree.Put(27, 10)
|
||||
// │ ┌── 27
|
||||
// │ ┌── 25
|
||||
// │ │ └── 22
|
||||
// │ ┌── 17
|
||||
// │ │ └── 15
|
||||
// └── 13
|
||||
// │ ┌── 11
|
||||
// └── 8
|
||||
// │ ┌── 6
|
||||
// └── 1
|
||||
it := tree.Iterator()
|
||||
count := 0
|
||||
for it.Next() {
|
||||
count++
|
||||
value := it.Value()
|
||||
switch value {
|
||||
case count:
|
||||
if actualValue, expectedValue := value, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
default:
|
||||
if actualValue, expectedValue := value, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
}
|
||||
if actualValue, expectedValue := count, tree.Size(); actualValue != expectedValue {
|
||||
t.Errorf("Size different. Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIterator4Prev(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(13, 5)
|
||||
tree.Put(8, 3)
|
||||
tree.Put(17, 7)
|
||||
tree.Put(1, 1)
|
||||
tree.Put(11, 4)
|
||||
tree.Put(15, 6)
|
||||
tree.Put(25, 9)
|
||||
tree.Put(6, 2)
|
||||
tree.Put(22, 8)
|
||||
tree.Put(27, 10)
|
||||
// │ ┌── 27
|
||||
// │ ┌── 25
|
||||
// │ │ └── 22
|
||||
// │ ┌── 17
|
||||
// │ │ └── 15
|
||||
// └── 13
|
||||
// │ ┌── 11
|
||||
// └── 8
|
||||
// │ ┌── 6
|
||||
// └── 1
|
||||
it := tree.Iterator()
|
||||
count := tree.Size()
|
||||
for it.Next() {
|
||||
}
|
||||
for it.Prev() {
|
||||
value := it.Value()
|
||||
switch value {
|
||||
case count:
|
||||
if actualValue, expectedValue := value, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
default:
|
||||
if actualValue, expectedValue := value, count; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
count--
|
||||
}
|
||||
if actualValue, expectedValue := count, 0; actualValue != expectedValue {
|
||||
t.Errorf("Size different. Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIteratorBegin(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(3, "c")
|
||||
tree.Put(1, "a")
|
||||
tree.Put(2, "b")
|
||||
it := tree.Iterator()
|
||||
|
||||
if it.Key() != nil {
|
||||
t.Errorf("Got %v expected %v", it.Key(), nil)
|
||||
}
|
||||
|
||||
it.Begin()
|
||||
|
||||
if it.Key() != nil {
|
||||
t.Errorf("Got %v expected %v", it.Key(), nil)
|
||||
}
|
||||
|
||||
for it.Next() {
|
||||
}
|
||||
|
||||
it.Begin()
|
||||
|
||||
if it.Key() != nil {
|
||||
t.Errorf("Got %v expected %v", it.Key(), nil)
|
||||
}
|
||||
|
||||
it.Next()
|
||||
if key, value := it.Key(), it.Value(); key != 1 || value != "a" {
|
||||
t.Errorf("Got %v,%v expected %v,%v", key, value, 1, "a")
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIteratorEnd(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
it := tree.Iterator()
|
||||
|
||||
if it.Key() != nil {
|
||||
t.Errorf("Got %v expected %v", it.Key(), nil)
|
||||
}
|
||||
|
||||
it.End()
|
||||
if it.Key() != nil {
|
||||
t.Errorf("Got %v expected %v", it.Key(), nil)
|
||||
}
|
||||
|
||||
tree.Put(3, "c")
|
||||
tree.Put(1, "a")
|
||||
tree.Put(2, "b")
|
||||
it.End()
|
||||
if it.Key() != nil {
|
||||
t.Errorf("Got %v expected %v", it.Key(), nil)
|
||||
}
|
||||
|
||||
it.Prev()
|
||||
if key, value := it.Key(), it.Value(); key != 3 || value != "c" {
|
||||
t.Errorf("Got %v,%v expected %v,%v", key, value, 3, "c")
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIteratorFirst(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(3, "c")
|
||||
tree.Put(1, "a")
|
||||
tree.Put(2, "b")
|
||||
it := tree.Iterator()
|
||||
if actualValue, expectedValue := it.First(), true; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if key, value := it.Key(), it.Value(); key != 1 || value != "a" {
|
||||
t.Errorf("Got %v,%v expected %v,%v", key, value, 1, "a")
|
||||
}
|
||||
}
|
||||
|
||||
func TestAVLTreeIteratorLast(t *testing.T) {
|
||||
tree := NewWithIntComparator()
|
||||
tree.Put(3, "c")
|
||||
tree.Put(1, "a")
|
||||
tree.Put(2, "b")
|
||||
it := tree.Iterator()
|
||||
if actualValue, expectedValue := it.Last(), true; actualValue != expectedValue {
|
||||
t.Errorf("Got %v expected %v", actualValue, expectedValue)
|
||||
}
|
||||
if key, value := it.Key(), it.Value(); key != 3 || value != "c" {
|
||||
t.Errorf("Got %v,%v expected %v,%v", key, value, 3, "c")
|
||||
}
|
||||
}
|
||||
|
||||
func benchmarkGet(b *testing.B, tree *Tree, size int) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Get(n)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func benchmarkPut(b *testing.B, tree *Tree, size int) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func benchmarkRemove(b *testing.B, tree *Tree, size int) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Remove(n)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreeGet100(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 100
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkGet(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreeGet1000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 1000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkGet(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreeGet10000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 10000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkGet(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreeGet100000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 100000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkGet(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreePut100(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 100
|
||||
tree := NewWithIntComparator()
|
||||
b.StartTimer()
|
||||
benchmarkPut(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreePut1000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 1000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkPut(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreePut10000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 10000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkPut(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreePut100000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 100000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkPut(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreeRemove100(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 100
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkRemove(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreeRemove1000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 1000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkRemove(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreeRemove10000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 10000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkRemove(b, tree, size)
|
||||
}
|
||||
|
||||
func BenchmarkAVLTreeRemove100000(b *testing.B) {
|
||||
b.StopTimer()
|
||||
size := 100000
|
||||
tree := NewWithIntComparator()
|
||||
for n := 0; n < size; n++ {
|
||||
tree.Put(n, struct{}{})
|
||||
}
|
||||
b.StartTimer()
|
||||
benchmarkRemove(b, tree, size)
|
||||
}
|
||||
@ -0,0 +1,117 @@
|
||||
// Copyright (c) 2017, Benjamin Scher Purcell. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package avltree
|
||||
|
||||
import "github.com/emirpasic/gods/containers"
|
||||
|
||||
func assertIteratorImplementation() {
|
||||
var _ containers.ReverseIteratorWithKey = (*Iterator)(nil)
|
||||
}
|
||||
|
||||
// Iterator holding the iterator's state
|
||||
type Iterator struct {
|
||||
tree *Tree
|
||||
node *Node
|
||||
position position
|
||||
}
|
||||
|
||||
type position byte
|
||||
|
||||
const (
|
||||
begin, between, end position = 0, 1, 2
|
||||
)
|
||||
|
||||
// Iterator returns a stateful iterator whose elements are key/value pairs.
|
||||
func (tree *Tree) Iterator() containers.ReverseIteratorWithKey {
|
||||
return &Iterator{tree: tree, node: nil, position: begin}
|
||||
}
|
||||
|
||||
// Next moves the iterator to the next element and returns true if there was a next element in the container.
|
||||
// If Next() returns true, then next element's key and value can be retrieved by Key() and Value().
|
||||
// If Next() was called for the first time, then it will point the iterator to the first element if it exists.
|
||||
// Modifies the state of the iterator.
|
||||
func (iterator *Iterator) Next() bool {
|
||||
switch iterator.position {
|
||||
case begin:
|
||||
iterator.position = between
|
||||
iterator.node = iterator.tree.Left()
|
||||
case between:
|
||||
iterator.node = iterator.node.Next()
|
||||
}
|
||||
|
||||
if iterator.node == nil {
|
||||
iterator.position = end
|
||||
return false
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// Prev moves the iterator to the next element and returns true if there was a previous element in the container.
|
||||
// If Prev() returns true, then next element's key and value can be retrieved by Key() and Value().
|
||||
// If Prev() was called for the first time, then it will point the iterator to the first element if it exists.
|
||||
// Modifies the state of the iterator.
|
||||
func (iterator *Iterator) Prev() bool {
|
||||
switch iterator.position {
|
||||
case end:
|
||||
iterator.position = between
|
||||
iterator.node = iterator.tree.Right()
|
||||
case between:
|
||||
iterator.node = iterator.node.Prev()
|
||||
}
|
||||
|
||||
if iterator.node == nil {
|
||||
iterator.position = begin
|
||||
return false
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// Value returns the current element's value.
|
||||
// Does not modify the state of the iterator.
|
||||
func (iterator *Iterator) Value() interface{} {
|
||||
if iterator.node == nil {
|
||||
return nil
|
||||
}
|
||||
return iterator.node.Value
|
||||
}
|
||||
|
||||
// Key returns the current element's key.
|
||||
// Does not modify the state of the iterator.
|
||||
func (iterator *Iterator) Key() interface{} {
|
||||
if iterator.node == nil {
|
||||
return nil
|
||||
}
|
||||
return iterator.node.Key
|
||||
}
|
||||
|
||||
// Begin resets the iterator to its initial state (one-before-first)
|
||||
// Call Next() to fetch the first element if any.
|
||||
func (iterator *Iterator) Begin() {
|
||||
iterator.node = nil
|
||||
iterator.position = begin
|
||||
}
|
||||
|
||||
// End moves the iterator past the last element (one-past-the-end).
|
||||
// Call Prev() to fetch the last element if any.
|
||||
func (iterator *Iterator) End() {
|
||||
iterator.node = nil
|
||||
iterator.position = end
|
||||
}
|
||||
|
||||
// First moves the iterator to the first element and returns true if there was a first element in the container.
|
||||
// If First() returns true, then first element's key and value can be retrieved by Key() and Value().
|
||||
// Modifies the state of the iterator
|
||||
func (iterator *Iterator) First() bool {
|
||||
iterator.Begin()
|
||||
return iterator.Next()
|
||||
}
|
||||
|
||||
// Last moves the iterator to the last element and returns true if there was a last element in the container.
|
||||
// If Last() returns true, then last element's key and value can be retrieved by Key() and Value().
|
||||
// Modifies the state of the iterator.
|
||||
func (iterator *Iterator) Last() bool {
|
||||
iterator.End()
|
||||
return iterator.Prev()
|
||||
}
|
||||
Loading…
Reference in New Issue