都是常用的功能。
删除是最复杂的。。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>test</title>
<script src="js/lib/angular.min.js"></script>
<script >
function BinarySearchTree(){
var Node = function(key){
this.key = key;
this.left = null;
this.right = null;
};
var root = null;
this.insert = function(key){
var newNode = new Node(key);
if (root === null) {
root = newNode;
} else {
insertNode(root, newNode);
}
};
var insertNode = function(node, newNode) {
if (newNode.key < node.key) {
if (node.left === null) {
node.left = newNode;
} else {
insertNode(node.left, newNode);
}
}else{
if (node.right == null) {
node.right = newNode;
} else {
insertNode(node.right, newNode);
}
}
};
this.inOrderTraverse = function(callback) {
inOrderTraverseNode(root, callback);
};
var inOrderTraverseNode = function(node, callback) {
if (node !== null) {
inOrderTraverseNode(node.left, callback);
callback(node.key);
inOrderTraverseNode(node.right, callback);
}
};
this.preOrderTraverse = function(callback){
preOrderTraverseNode(root, callback);
};
var preOrderTraverseNode = function (node, callback) {
if (node !== null) {
callback(node.key); //{1}
preOrderTraverseNode(node.left, callback); //{2}
preOrderTraverseNode(node.right, callback); //{3}
}
};
this.postOrderTraverse = function(callback){
postOrderTraverseNode(root, callback);
};
var postOrderTraverseNode = function (node, callback) {
if (node !== null) {
postOrderTraverseNode(node.left, callback); //{1}
postOrderTraverseNode(node.right, callback); //{2}
callback(node.key); //{3}
}
};
this.min = function() {
return minNode(root);
};
var minNode = function(node) {
if (node) {
while (node && node.left !== null) {
node = node.left;
}
return node.key;
}
return null;
};
this.max = function() {
return maxNode(root);
};
var maxNode = function (node) {
if (node){
while (node && node.right !== null) { //{5}
node = node.right;
}
return node.key;
}
return null;
};
this.search = function(key) {
return searchNode(root, key);
};
var searchNode = function(node, key) {
if (node === null) {
return false;
}
if (key < node.key) {
return searchNode(node.left, key);
} else if (key > node.key) {
return searchNode(node.right, key);
}else{
return true;
}
};
this.remove = function(key) {
root = removeNode(root, key);
};
var removeNode = function(node, key){
if (node === null){ //{2}
return null;
}
if (key < node.key){ //{3}
node.left = removeNode(node.left, key); //{4}
return node; //{5}
} else if (key > node.key){ //{6}
node.right = removeNode(node.right, key); //{7}
return node; //{8}
} else { //键等于node.key
//第一种情况——一个叶节点
if (node.left === null && node.right === null){ //{9}
node = null; //{10}
return node; //{11}
}
//第二种情况——一个只有一个子节点的节点
if (node.left === null){ //{12}
node = node.right; //{13}
return node; //{14}
} else if (node.right === null){ //{15}
node = node.left; //{16}
return node; //{17}
}
//第三种情况——一个有两个子节点的节点
var aux = findMinNode(node.right); //{18}
node.key = aux.key; //{19}
node.right = removeNode(node.right, aux.key); //{20}
return node; //{21}
}
};
}
function printNode(value) {
console.log(value);
}
var tree = new BinarySearchTree();
tree.insert(11);
tree.insert(7);
tree.insert(15);
tree.insert(5);
tree.insert(3);
tree.insert(9);
tree.insert(8);
tree.insert(10);
tree.insert(13);
tree.insert(12);
tree.insert(14);
tree.insert(20);
tree.insert(18);
tree.insert(25);
tree.insert(6);
tree.inOrderTraverse(printNode);
tree.preOrderTraverse(printNode);
tree.postOrderTraverse(printNode);
console.log(tree.min());
console.log(tree.max());
console.log(tree.search(1) ? 'Key 1 found.' : 'Key 1 not found.');
console.log(tree.search(8) ? 'Key 8 found.' : 'Key 8 not found.');
</script>
</head>
<body>
</body>
</html>
