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@ -18,10 +18,12 @@ with this distribution for more information.
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// Implementation of Red-black tree.
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// Used by TreeSet and TreeMap.
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// Structure is not thread safe.
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// References: http://en.wikipedia.org/wiki/Red%E2%80%93black_tree
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package redblacktree
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import (
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"fmt"
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"github.com/emirpasic/gods/utils"
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)
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@ -121,18 +123,20 @@ func (tree *Tree) Remove(key interface{}) {
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node.value = pred.value
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node = pred
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}
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if node.right == nil {
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child = node.left
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} else {
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child = node.right
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}
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if node.color == BLACK {
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node.color = child.color
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tree.deleteCase1(node)
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}
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tree.replaceNode(node, child)
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if node.parent == nil && child != nil {
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child.color = BLACK
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if node.left == nil || node.right == nil {
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if node.right == nil {
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child = node.left
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} else {
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child = node.right
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}
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if node.color == BLACK {
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node.color = child.color
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tree.deleteCase1(node)
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}
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tree.replaceNode(node, child)
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if node.parent == nil && child != nil {
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child.color = BLACK
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}
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}
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}
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@ -141,6 +145,39 @@ func (tree *Tree) IsEmpty() bool {
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return tree.root == nil
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}
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func (tree *Tree) String() string {
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if !tree.IsEmpty() {
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levels := make(map[int][]*Node)
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lastLevel := 0
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levels[lastLevel] = append(levels[lastLevel], tree.root)
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for len(levels[lastLevel]) > 0 {
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for _, node := range levels[lastLevel] {
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if node.left != nil {
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levels[lastLevel+1] = append(levels[lastLevel+1], node.left)
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}
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if node.right != nil {
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levels[lastLevel+1] = append(levels[lastLevel+1], node.right)
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}
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}
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lastLevel += 1
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}
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str := "tree\n"
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for i := 0; i < lastLevel; i++ {
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for _, node := range levels[i] {
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str += fmt.Sprintf("%s", node)
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}
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str += "\n"
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}
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return str
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}
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return "tree\n"
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}
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func (node *Node) String() string {
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return fmt.Sprintf("(%v)", node.key)
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}
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func (tree *Tree) lookup(key interface{}) *Node {
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node := tree.root
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for node != nil {
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@ -347,10 +384,10 @@ func (tree *Tree) deleteCase5(node *Node) {
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func (tree *Tree) deleteCase6(node *Node) {
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node.sibling().color = node.parent.color
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node.parent.color = BLACK
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if node == node.parent.left {
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if node == node.parent.left && node.sibling().right.color == RED {
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node.sibling().right.color = BLACK
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tree.rotateLeft(node.parent)
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} else {
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} else if node.sibling().left.color == RED {
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node.sibling().left.color = BLACK
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tree.rotateRight(node.parent)
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}
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