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- unexporting node struct and color constants (keeping the lib clean)

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pull/1/head
Emir Pasic 10 years ago
parent e04668c20d
commit 14efefae45
1 changed files with 74 additions and 74 deletions
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148
trees/redblacktree/redblacktree.go
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@ -27,25 +27,25 @@ import (
"github.com/emirpasic/gods/utils"
)
type Color bool
type color bool
const (
BLACK, RED Color = true, false
black, red color = true, false
)
type Tree struct {
root *Node
root *node
size int
comparator utils.Comparator
}
type Node struct {
type node struct {
key interface{}
value interface{}
color Color
left *Node
right *Node
parent *Node
color color
left *node
right *node
parent *node
}
// Instantiates a red-black tree with the custom comparator.
@ -66,7 +66,7 @@ func NewWithStringComparator() *Tree {
// Inserts node into the tree.
// Key should adhere to the comparator's type assertion, otherwise method panics.
func (tree *Tree) Put(key interface{}, value interface{}) {
insertedNode := &Node{key: key, value: value, color: RED}
insertedNode := &node{key: key, value: value, color: red}
if tree.root == nil {
tree.root = insertedNode
} else {
@ -114,7 +114,7 @@ func (tree *Tree) Get(key interface{}) (interface{}, bool) {
// Remove the node from the tree by key.
// Key should adhere to the comparator's type assertion, otherwise method panics.
func (tree *Tree) Remove(key interface{}) {
var child *Node
var child *node
node := tree.lookup(key)
if node == nil {
return
@ -131,13 +131,13 @@ func (tree *Tree) Remove(key interface{}) {
} else {
child = node.right
}
if node.color == BLACK {
node.color = color(child)
if node.color == black {
node.color = nodeColor(child)
tree.deleteCase1(node)
}
tree.replaceNode(node, child)
if node.parent == nil && child != nil {
child.color = BLACK
child.color = black
}
}
tree.size -= 1
@ -161,11 +161,11 @@ func (tree *Tree) String() string {
return str
}
func (node *Node) String() string {
func (node *node) String() string {
return fmt.Sprintf("%v", node.key)
}
func output(node *Node, prefix string, isTail bool, str *string) {
func output(node *node, prefix string, isTail bool, str *string) {
if node.right != nil {
newPrefix := prefix
if isTail {
@ -193,7 +193,7 @@ func output(node *Node, prefix string, isTail bool, str *string) {
}
}
func (tree *Tree) lookup(key interface{}) *Node {
func (tree *Tree) lookup(key interface{}) *node {
node := tree.root
for node != nil {
compare := tree.comparator(key, node.key)
@ -209,21 +209,21 @@ func (tree *Tree) lookup(key interface{}) *Node {
return nil
}
func (node *Node) grandparent() *Node {
func (node *node) grandparent() *node {
if node != nil && node.parent != nil {
return node.parent.parent
}
return nil
}
func (node *Node) uncle() *Node {
func (node *node) uncle() *node {
if node == nil || node.parent == nil || node.parent.parent == nil {
return nil
}
return node.parent.sibling()
}
func (node *Node) sibling() *Node {
func (node *node) sibling() *node {
if node == nil || node.parent == nil {
return nil
}
@ -234,7 +234,7 @@ func (node *Node) sibling() *Node {
}
}
func (tree *Tree) rotateLeft(node *Node) {
func (tree *Tree) rotateLeft(node *node) {
right := node.right
tree.replaceNode(node, right)
node.right = right.left
@ -245,7 +245,7 @@ func (tree *Tree) rotateLeft(node *Node) {
node.parent = right
}
func (tree *Tree) rotateRight(node *Node) {
func (tree *Tree) rotateRight(node *node) {
left := node.left
tree.replaceNode(node, left)
node.left = left.right
@ -256,7 +256,7 @@ func (tree *Tree) rotateRight(node *Node) {
node.parent = left
}
func (tree *Tree) replaceNode(old *Node, new *Node) {
func (tree *Tree) replaceNode(old *node, new *node) {
if old.parent == nil {
tree.root = new
} else {
@ -271,34 +271,34 @@ func (tree *Tree) replaceNode(old *Node, new *Node) {
}
}
func (tree *Tree) insertCase1(node *Node) {
func (tree *Tree) insertCase1(node *node) {
if node.parent == nil {
node.color = BLACK
node.color = black
} else {
tree.insertCase2(node)
}
}
func (tree *Tree) insertCase2(node *Node) {
if color(node.parent) == BLACK {
func (tree *Tree) insertCase2(node *node) {
if nodeColor(node.parent) == black {
return
}
tree.insertCase3(node)
}
func (tree *Tree) insertCase3(node *Node) {
func (tree *Tree) insertCase3(node *node) {
uncle := node.uncle()
if color(uncle) == RED {
node.parent.color = BLACK
uncle.color = BLACK
node.grandparent().color = RED
if nodeColor(uncle) == red {
node.parent.color = black
uncle.color = black
node.grandparent().color = red
tree.insertCase1(node.grandparent())
} else {
tree.insertCase4(node)
}
}
func (tree *Tree) insertCase4(node *Node) {
func (tree *Tree) insertCase4(node *node) {
grandparent := node.grandparent()
if node == node.parent.right && node.parent == grandparent.left {
tree.rotateLeft(node.parent)
@ -310,10 +310,10 @@ func (tree *Tree) insertCase4(node *Node) {
tree.insertCase5(node)
}
func (tree *Tree) insertCase5(node *Node) {
node.parent.color = BLACK
func (tree *Tree) insertCase5(node *node) {
node.parent.color = black
grandparent := node.grandparent()
grandparent.color = RED
grandparent.color = red
if node == node.parent.left && node.parent == grandparent.left {
tree.rotateRight(grandparent)
} else if node == node.parent.right && node.parent == grandparent.right {
@ -321,7 +321,7 @@ func (tree *Tree) insertCase5(node *Node) {
}
}
func (node *Node) maximumNode() *Node {
func (node *node) maximumNode() *node {
if node == nil {
return nil
}
@ -331,7 +331,7 @@ func (node *Node) maximumNode() *Node {
return node
}
func (tree *Tree) deleteCase1(node *Node) {
func (tree *Tree) deleteCase1(node *node) {
if node.parent == nil {
return
} else {
@ -339,11 +339,11 @@ func (tree *Tree) deleteCase1(node *Node) {
}
}
func (tree *Tree) deleteCase2(node *Node) {
func (tree *Tree) deleteCase2(node *node) {
sibling := node.sibling()
if color(sibling) == RED {
node.parent.color = RED
sibling.color = BLACK
if nodeColor(sibling) == red {
node.parent.color = red
sibling.color = black
if node == node.parent.left {
tree.rotateLeft(node.parent)
} else {
@ -353,68 +353,68 @@ func (tree *Tree) deleteCase2(node *Node) {
tree.deleteCase3(node)
}
func (tree *Tree) deleteCase3(node *Node) {
func (tree *Tree) deleteCase3(node *node) {
sibling := node.sibling()
if color(node.parent) == BLACK &&
color(sibling) == BLACK &&
color(sibling.left) == BLACK &&
color(sibling.right) == BLACK {
sibling.color = RED
if nodeColor(node.parent) == black &&
nodeColor(sibling) == black &&
nodeColor(sibling.left) == black &&
nodeColor(sibling.right) == black {
sibling.color = red
tree.deleteCase1(node.parent)
} else {
tree.deleteCase4(node)
}
}
func (tree *Tree) deleteCase4(node *Node) {
func (tree *Tree) deleteCase4(node *node) {
sibling := node.sibling()
if color(node.parent) == RED &&
color(sibling) == BLACK &&
color(sibling.left) == BLACK &&
color(sibling.right) == BLACK {
sibling.color = RED
node.parent.color = BLACK
if nodeColor(node.parent) == red &&
nodeColor(sibling) == black &&
nodeColor(sibling.left) == black &&
nodeColor(sibling.right) == black {
sibling.color = red
node.parent.color = black
} else {
tree.deleteCase5(node)
}
}
func (tree *Tree) deleteCase5(node *Node) {
func (tree *Tree) deleteCase5(node *node) {
sibling := node.sibling()
if node == node.parent.left &&
color(sibling) == BLACK &&
color(sibling.left) == RED &&
color(sibling.right) == BLACK {
sibling.color = RED
sibling.left.color = BLACK
nodeColor(sibling) == black &&
nodeColor(sibling.left) == red &&
nodeColor(sibling.right) == black {
sibling.color = red
sibling.left.color = black
tree.rotateRight(sibling)
} else if node == node.parent.right &&
color(sibling) == BLACK &&
color(sibling.right) == RED &&
color(sibling.left) == BLACK {
sibling.color = RED
sibling.right.color = BLACK
nodeColor(sibling) == black &&
nodeColor(sibling.right) == red &&
nodeColor(sibling.left) == black {
sibling.color = red
sibling.right.color = black
tree.rotateLeft(sibling)
}
tree.deleteCase6(node)
}
func (tree *Tree) deleteCase6(node *Node) {
func (tree *Tree) deleteCase6(node *node) {
sibling := node.sibling()
sibling.color = color(node.parent)
node.parent.color = BLACK
if node == node.parent.left && color(sibling.right) == RED {
sibling.right.color = BLACK
sibling.color = nodeColor(node.parent)
node.parent.color = black
if node == node.parent.left && nodeColor(sibling.right) == red {
sibling.right.color = black
tree.rotateLeft(node.parent)
} else if color(sibling.left) == RED {
sibling.left.color = BLACK
} else if nodeColor(sibling.left) == red {
sibling.left.color = black
tree.rotateRight(node.parent)
}
}
func color(node *Node) Color {
func nodeColor(node *node) color {
if node == nil {
return BLACK
return black
}
return node.color
}

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