// Copyright (c) 2015, Emir Pasic. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package redblacktreeextended import ( "fmt" rbt "github.com/emirpasic/gods/v2/trees/redblacktree" ) // RedBlackTreeExtended to demonstrate how to extend a RedBlackTree to include new functions type RedBlackTreeExtended[K comparable, V any] struct { *rbt.Tree[K, V] } // GetMin gets the min value and flag if found func (tree *RedBlackTreeExtended[K, V]) GetMin() (value V, found bool) { node, found := tree.getMinFromNode(tree.Root) if found { return node.Value, found } return value, false } // GetMax gets the max value and flag if found func (tree *RedBlackTreeExtended[K, V]) GetMax() (value V, found bool) { node, found := tree.getMaxFromNode(tree.Root) if found { return node.Value, found } return value, false } // RemoveMin removes the min value and flag if found func (tree *RedBlackTreeExtended[K, V]) RemoveMin() (value V, deleted bool) { node, found := tree.getMinFromNode(tree.Root) if found { tree.Remove(node.Key) return node.Value, found } return value, false } // RemoveMax removes the max value and flag if found func (tree *RedBlackTreeExtended[K, V]) RemoveMax() (value V, deleted bool) { node, found := tree.getMaxFromNode(tree.Root) if found { tree.Remove(node.Key) return node.Value, found } return value, false } func (tree *RedBlackTreeExtended[K, V]) getMinFromNode(node *rbt.Node[K, V]) (foundNode *rbt.Node[K, V], found bool) { if node == nil { return nil, false } if node.Left == nil { return node, true } return tree.getMinFromNode(node.Left) } func (tree *RedBlackTreeExtended[K, V]) getMaxFromNode(node *rbt.Node[K, V]) (foundNode *rbt.Node[K, V], found bool) { if node == nil { return nil, false } if node.Right == nil { return node, true } return tree.getMaxFromNode(node.Right) } func print(tree *RedBlackTreeExtended[int, string]) { max, _ := tree.GetMax() min, _ := tree.GetMin() fmt.Printf("Value for max key: %v \n", max) fmt.Printf("Value for min key: %v \n", min) fmt.Println(tree) } // RedBlackTreeExtendedExample main method on how to use the custom red-black tree above func main() { tree := RedBlackTreeExtended[int, string]{rbt.New[int, string]()} tree.Put(1, "a") // 1->x (in order) tree.Put(2, "b") // 1->x, 2->b (in order) tree.Put(3, "c") // 1->x, 2->b, 3->c (in order) tree.Put(4, "d") // 1->x, 2->b, 3->c, 4->d (in order) tree.Put(5, "e") // 1->x, 2->b, 3->c, 4->d, 5->e (in order) print(&tree) // Value for max key: e // Value for min key: a // RedBlackTree // │ ┌── 5 // │ ┌── 4 // │ │ └── 3 // └── 2 // └── 1 tree.RemoveMin() // 2->b, 3->c, 4->d, 5->e (in order) tree.RemoveMax() // 2->b, 3->c, 4->d (in order) tree.RemoveMin() // 3->c, 4->d (in order) tree.RemoveMax() // 3->c (in order) print(&tree) // Value for max key: c // Value for min key: c // RedBlackTree // └── 3 }