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);