结构算法

// 二叉树
function BinaryTree() {
    this.root = null;
    this.node = function (val) {return {val: val, left: null, right: null}};
    this.add  = function (val) {
        if (this.root === null) {
            this.root = this.node(val);
        }
        else {
            var current = this.root;
            var parent;

            while (true) {
                parent = current;
                if (val < current.val) {
                    current = current.left;
                    if (current === null) {
                        parent.left = this.node(val);
                        break;
                    }
                }
                else {
                    current = current.right;
                    if (current === null) {
                        parent.right = this.node(val);
                        break;
                    }
                }
            }
        }
    };
}