(一)构造二叉树
function BinaryTree(){
var Node = function (key) {
this.key = key;
this.left = null;
this.right = null;
}
var root = null;
// 构造二叉树
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)
}
}
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
nodes.forEach(function(key){
binaryTree.insert(key)
})
(二)中序遍历
function BinaryTree(){
//...
// 中序遍历
var inOrderTraverseNode = function (node, callback) {
if (node !== null) {
inOrderTraverseNode(node.left, callback)
callback(node.key)
inOrderTraverseNode(node.right, callback)
}
}
this.inOrderTraverse = function (callback) {
inOrderTraverseNode(root, callback)
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
//nodes.forEach(function(key){
// binaryTree.insert(key)
//})
var callback = function (key) {
console.log(key)
}
binaryTree.inOrderTraverse(callback)
(三)前序遍历
前序遍历可以复制二叉树,效率比重新构造二叉树高
function BinaryTree(){
// ...
// 前序遍历
var preOrderTraverseNode = function (node, callback) {
if (node !== null) {
callback(node.key)
preOrderTraverseNode(node.left, callback)
preOrderTraverseNode(node.right, callback)
}
}
this.preOrderTraverse = function (callback) {
preOrderTraverseNode(root, callback)
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
//nodes.forEach(function(key){
// binaryTree.insert(key)
//})
var callback = function (key) {
console.log(key)
}
//binaryTree.inOrderTraverse(callback)
binaryTree.preOrderTraverse(callback)
(四)后序遍历
当要删除操作系统中的文件时,可以利用后序遍历,查看当前路径下还有没有文件,没有即可删除
function BinaryTree(){
// ...
// 后序遍历
var postOrderTraverseNode = function (node, callback) {
if (node !== null) {
postOrderTraverseNode(node.left, callback)
postOrderTraverseNode(node.right, callback)
callback(node.key)
}
}
this.postOrderTraverse = function (callback) {
postOrderTraverseNode(root, callback)
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
//nodes.forEach(function(key){
// binaryTree.insert(key)
//})
var callback = function (key) {
console.log(key)
}
//binaryTree.inOrderTraverse(callback)
//binaryTree.preOrderTraverse(callback)
binaryTree.postOrderTraverse(callback)
(五)查找最小值
function BinaryTree(){
// ...
// 查找最小值
var minNode = function (node) {
if (node) {
while (node && node.left !== null) {
node = node.left
}
return node.key
}
return null
}
this.min = function () {
return minNode (root)
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
//nodes.forEach(function(key){
// binaryTree.insert(key)
//})
var callback = function (key) {
console.log(key)
}
//binaryTree.inOrderTraverse(callback)
//binaryTree.preOrderTraverse(callback)
//binaryTree.postOrderTraverse(callback)
console.log("min node is: " + binaryTree.min())
(六)查找最大值
function BinaryTree(){
// ...
// 查找最大值
var maxNode = function (node) {
if (node) {
while (node && node.right !== null) {
node = node.right
}
return node.key
}
return null
}
this.max = function () {
return maxNode(root)
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
//nodes.forEach(function(key){
// binaryTree.insert(key)
//})
var callback = function (key) {
console.log(key)
}
//binaryTree.inOrderTraverse(callback)
//binaryTree.preOrderTraverse(callback)
//binaryTree.postOrderTraverse(callback)
//console.log("min node is: " + binaryTree.min())
console.log("max node is: " + binaryTree.max())
(七)查找给定值
function BinaryTree(){
// ...
// 查找给定值
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.search = function (key) {
return searchNode(root, key)
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
//nodes.forEach(function(key){
// binaryTree.insert(key)
//})
var callback = function (key) {
console.log(key)
}
//binaryTree.inOrderTraverse(callback)
//binaryTree.preOrderTraverse(callback)
//binaryTree.postOrderTraverse(callback)
//console.log("min node is: " + binaryTree.min())
//console.log("max node is: " + binaryTree.max())
console.log(binaryTree.search(3) ? 'key 3 is found' : 'key 3 is not found')
(八)删除指定节点
function BinaryTree(){
// ...
// 删除指定节点
var removeNode = function (node, key) {
if (node === null) {
return null
}
if (key < node.key) {
node.left = removeNode(node.left, key)
return node
} else if (key > node.key) {
node.right = removeNode(node.right, key)
return node
} else {
if (node.left === null && node.right === null) {
node = null
return node
}
if (node.left === null) {
node = node.right
return node
} else if (node.right === null) {
node = node.right
return node
}
// 删除节点有两个子节点时
// 找到右子树中最小节点替换删除的节点
var aux = findMinNode(node.right)
node.key = aux.key
node.right = removeNode(node.right, aux)
}
}
this.remove= function (key) {
root = removeNode(root, key)
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
//nodes.forEach(function(key){
// binaryTree.insert(key)
//})
var callback = function (key) {
console.log(key)
}
//binaryTree.inOrderTraverse(callback)
//binaryTree.preOrderTraverse(callback)
//binaryTree.postOrderTraverse(callback)
//console.log("min node is: " + binaryTree.min())
//console.log("max node is: " + binaryTree.max())
//console.log(binaryTree.search(3) ? 'key 3 is found' : 'key 3 is not found')
binaryTree.remove(23)
完整代码如下:
function BinaryTree(){
var Node = function (key) {
this.key = key;
this.left = null;
this.right = null;
}
var root = null;
// 构造二叉树
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)
}
}
}
// 中序遍历
var inOrderTraverseNode = function (node, callback) {
if (node !== null) {
inOrderTraverseNode(node.left, callback)
callback(node.key)
inOrderTraverseNode(node.right, callback)
}
}
this.inOrderTraverse = function (callback) {
inOrderTraverseNode(root, callback)
}
// 前序遍历
var preOrderTraverseNode = function (node, callback) {
if (node !== null) {
callback(node.key)
preOrderTraverseNode(node.left, callback)
preOrderTraverseNode(node.right, callback)
}
}
this.preOrderTraverse = function (callback) {
preOrderTraverseNode(root, callback)
}
// 后序遍历
var postOrderTraverseNode = function (node, callback) {
if (node !== null) {
postOrderTraverseNode(node.left, callback)
postOrderTraverseNode(node.right, callback)
callback(node.key)
}
}
this.postOrderTraverse = function (callback) {
postOrderTraverseNode(root, callback)
}
// 查找最小值
var minNode = function (node) {
if (node) {
while (node && node.left !== null) {
node = node.left
}
return node.key
}
return null
}
this.min = function () {
return minNode (root)
}
// 查找最大值
var maxNode = function (node) {
if (node) {
while (node && node.right !== null) {
node = node.right
}
return node.key
}
return null
}
this.max = function () {
return maxNode(root)
}
// 查找给定值
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.search = function (key) {
return searchNode(root, key)
}
// 查找最小值
var findMinNode = function (node) {
if (node) {
while (node && node.left !== null) {
node = node.left
}
return node
}
return null
}
// 删除指定节点
var removeNode = function (node, key) {
if (node === null) {
return null
}
if (key < node.key) {
node.left = removeNode(node.left, key)
return node
} else if (key > node.key) {
node.right = removeNode(node.right, key)
return node
} else {
if (node.left === null && node.right === null) {
node = null
return node
}
if (node.left === null) {
node = node.right
return node
} else if (node.right === null) {
node = node.right
return node
}
// 删除节点有两个子节点时
// 找到右子树中最小节点替换删除的节点
var aux = findMinNode(node.right)
node.key = aux.key
node.right = removeNode(node.right, aux)
}
}
this.remove= function (key) {
root = removeNode(root, key)
}
}
var nodes = [1,2,3,2,14,23,9,17,13,6]
var binaryTree = new BinaryTree()
nodes.forEach(function(key){
binaryTree.insert(key)
})
var callback = function (key) {
console.log(key)
}
binaryTree.inOrderTraverse(callback)
binaryTree.preOrderTraverse(callback)
binaryTree.postOrderTraverse(callback)
console.log("min node is: " + binaryTree.min())
console.log("max node is: " + binaryTree.max())
console.log(binaryTree.search(3) ? 'key 3 is found' : 'key 3 is not found')
binaryTree.remove(23)
网友评论