javascript数据结构与算法---二叉树（删除节点）

javascript数据结构与算法---二叉树（删除节点）

function Node(data,left,right) {
    this.data = data;
    this.left = left;
    this.right = right;
    this.show = show;
}

function show() {
    return this.data;
}

function BST() {
    this.root = null;
    this.insert = insert;
    this.inOrder = inOrder;
    this.getMin = getMin;
    this.getMax = getMax;
    this.find = find;
    this.remove = remove;
}

function insert(data) {
    var n = new Node(data,null,null);
    if(this.root == null) {
        this.root = n;
    }else {
        var current = this.root;
        var parent;
        while(current) {
            parent = current;
            if(data <  current.data) {
                current = current.left;
                if(current == null) {
                    parent.left = n;
                    break;
                }
            }else {
                current = current.right;
                if(current == null) {
                    parent.right = n;
                    break;
                }
            }
        }
    }
}
// 中序遍历
function inOrder(node) {
    if(!(node == null)) {
        inOrder(node.left);
        console.log(node.show());
        inOrder(node.right);
    }
}

// 先序遍历 
function preOrder(node) {
    if(!(node == null)) {
        console.log(node.show());
        preOrder(node.left);
        preOrder(node.right);
    }
}

// 后序遍历
function postOrder(node) {
    if(!(node == null)) {
        postOrder(node.left);
        postOrder(node.right);
        console.log("后序遍历"+node.show());
    }
}

// 二叉树查找最小值
function getMin(){
    var current = this.root;
    while(!(current.left == null)) {
        current = current.left;
    }
    return current.data;
}

// 二叉树上查找最大值
function getMax() {
    var current = this.root;
    while(!(current.right == null)) {
        current = current.right;
    }
    return current.data;
}

// 查找给定值
function find(data) {
    var current = this.root;
    while(current != null) {
        if(current.data == data) {
            return current;
        }else if(data < current.data) {
            current = current.left;
        }else {
            current = current.right;
        }
    }
    return null;
}

function remove(data) {
    root = removeNode(this.root,data);
}
function getSmallest(node) {
   if (node.left == null) {
      return node;
   }
   else {
      return getSmallest(node.left);
   }
}
function removeNode(node,data) {
    if(node == null) {
        return null;
    }
    if(data == node.data) {
        // 没有子节点的节点
        if(node.left == null && node.right == null) {
            return null;
        } 
        // 没有左子节点的节点
        if(node.left == null) {
            return node.right;
        }
        // 没有右子节点的节点
        if(node.right == null) {
            return node.left;
        }
        // 有2个子节点的节点
        var tempNode = getSmallest(node.right);
        node.data = tempNode.data;
        node.right = removeNode(node.right,tempNode.data);
        return node;
    }else if(data < node.data) {
        node.left = removeNode(node.left,data);
        return node;
    }else {
        node.right = removeNode(node.right,data);
        return node;
    }
}
代码初始化如下：
var nums = new BST();
nums.insert(23);
nums.insert(45);
nums.insert(16);
nums.insert(37);
nums.insert(3);
nums.insert(99);
nums.insert(22);
var min = nums.getMin();
console.log(min);
var max = nums.getMax();
console.log(max);
var value = nums.find("45");
console.log(value);
nums.remove(23);