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loianeloiane
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AVL tree code
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4 files changed

+218
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‎chapter08/02-UsingBinarySearchTree.js

+5-1
Original file line numberDiff line numberDiff line change
@@ -49,4 +49,8 @@ tree.remove(15);
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tree.inOrderTraverse(printNode);
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console.log('********* raw data structure ***********');
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console.log(tree.getRoot());
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console.log(tree.getRoot());
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console.log('********* printing HTML tree ***********');
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var parent = document.getElementsByTagName('body')[0];
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printHTMLTree(tree.getRoot(), parent, 255);

‎chapter08/03-AVLTree.js

+149
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,149 @@
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function AVLTree() {
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var Node = function(key){
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this.key = key;
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this.left = null;
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this.right = null;
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};
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var root = null;
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this.getRoot = function(){
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return root;
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};
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var heightNode = function(node) {
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if (node === null) {
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return -1;
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} else {
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return Math.max(heightNode(node.left), heightNode(node.right)) + 1;
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}
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};
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var rotationLL = function(node) {
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var tmp = node.left;
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node.left = tmp.right;
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tmp.right = node;
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return tmp;
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};
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var rotationRR = function(node) {
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var tmp = node.right;
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node.right = tmp.left;
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tmp.left = node;
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return tmp;
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};
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var rotationLR = function(node) {
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node.left = rotationRR(node.left);
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return rotationLL(node);
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};
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var rotationRL = function(node) {
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node.right = rotationLL(node.right);
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return rotationRR(node);
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};
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var insertNode = function(node, element) {
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if (node === null) {
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node = new Node(element);
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} else if (element < node.key) {
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node.left = insertNode(node.left, element);
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if (node.left !== null) {
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if ((heightNode(node.left) - heightNode(node.right)) > 1){
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if (element < node.left.key){
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node = rotationLL(node);
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} else {
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node = rotationLR(node);
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}
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}
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}
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} else if (element > node.key) {
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node.right = insertNode(node.right, element);
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if (node.right !== null) {
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if ((heightNode(node.right) - heightNode(node.left)) > 1){
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if (element > node.right.key){
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node = rotationRR(node);
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} else {
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node = rotationRL(node);
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}
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}
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}
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}
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return node;
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};
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this.insert = function(element) {
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root = insertNode(root, element);
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};
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var parentNode;
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var nodeToBeDeleted;
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var removeNode = function(node, element) {
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if (node === null) {
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return null;
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}
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parentNode = node;
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if (element < node.key) {
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node.left = removeNode(node.left, element);
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} else {
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nodeToBeDeleted = node;
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node.right = removeNode(node.right, element);
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}
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if (node === parentNode) { //remove node
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if (nodeToBeDeleted !== null && element === nodeToBeDeleted.key) {
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if (nodeToBeDeleted === parentNode) {
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node = node.left;
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} else {
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var tmp = nodeToBeDeleted.key;
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nodeToBeDeleted.key = parentNode.key;
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parentNode.key = tmp;
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node = node.right;
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}
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}
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} else { //do balancing
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if (node.left === undefined) node.left = null;
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if (node.right === undefined) node.right = null;
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if ((heightNode(node.left) - heightNode(node.right)) === 2) {
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if (element < node.left.key) {
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node = rotationLR(node);
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} else {
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node = rotationLL(node);
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}
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}
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if ((heightNode(node.right) - heightNode(node.left)) === 2) {
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if (element > node.right.key) {
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node = rotationRL(node);
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} else {
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node = rotationRR(node);
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}
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}
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}
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return node;
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};
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this.remove = function(element) {
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parentNode = null;
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nodeToBeDeleted = null;
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root = removeNode(root, element);
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};
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}

‎chapter08/04-UsingAVLTree.html

+2-2
Original file line numberDiff line numberDiff line change
@@ -5,7 +5,7 @@
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<title></title>
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</head>
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<body>
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<script type="text/javascript" src="03-AVLTree.js"></script>
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<script type="text/javascript" src="04-UsingAVLTree.js"></script>
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<script src="03-AVLTree.js"></script>
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<script src="04-UsingAVLTree.js"></script>
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</body>
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</html>

‎chapter08/04-UsingAVLTree.js

+62
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,62 @@
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var avlTree = new AVLTree();
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avlTree.insert(1);
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avlTree.insert(2);
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avlTree.insert(3);
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avlTree.insert(4);
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avlTree.insert(5);
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avlTree.insert(6);
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avlTree.insert(7);
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avlTree.insert(14);
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avlTree.insert(15);
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avlTree.insert(13);
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avlTree.insert(12);
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avlTree.insert(11);
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//RR rotation
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/*avlTree.insert(50);
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avlTree.insert(30);
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avlTree.insert(70);
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avlTree.insert(60);
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avlTree.insert(80);
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avlTree.insert(90);*/
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//LL rotation
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/*avlTree.insert(50);
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avlTree.insert(30);
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avlTree.insert(70);
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avlTree.insert(10);
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avlTree.insert(40);
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avlTree.insert(5);*/
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//LR rotation
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/*avlTree.insert(50);
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avlTree.insert(30);
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avlTree.insert(70);
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avlTree.insert(40);
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avlTree.insert(10);
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avlTree.insert(35);*/
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//RL rotation
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/*avlTree.insert(70);
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avlTree.insert(50);
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avlTree.insert(80);
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avlTree.insert(72);
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avlTree.insert(90);
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avlTree.insert(75);*/
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console.log('********* raw data structure ***********');
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console.log(avlTree.getRoot());
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/*avlTree.remove(12);
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avlTree.remove(15);
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avlTree.remove(11);
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avlTree.remove(14);
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avlTree.remove(13);
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avlTree.remove(7);
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avlTree.remove(6);
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avlTree.remove(2);
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avlTree.remove(4);
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console.log(avlTree.getRoot());*/
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