js实现输入某串数字，构建完全二叉树，并判断是否为二叉搜索树

思路：若为二叉搜索树，则中序遍历为递增的

let arr = [15,8,16,6,10];
let pindex = [];
function Node(){
this.root = null;
this.left = null;
this.right = null;
}

//构建完全二叉树
function CCtree(node,i){
let leftIndex = 2*i+1;
let rightIndex = 2*i+2;

if(leftIndex < arr.length){
let newNode = new Node();
newNode.root = arr[leftIndex];
node.left = newNode;
CCtree(newNode,leftIndex);
}
if(rightIndex < arr.length){
let newNode = new Node();
newNode.root = arr[rightIndex];
node.right = newNode;
CCtree(newNode, rightIndex);
}
}

//中序遍历

function VinIndex(node){
if(node.left){
if(node.left.left){
VinIndex(node.left);
}
else{
pindex.push(node.left.root);
}
}
pindex.push(node.root);
if(node.right){
if(node.right.left){
VinIndex(node.right)
}
else{
pindex.push(node.right.root);
}
}
}
var node = new Node();
node.root = arr[0];
CCtree(node, 0); //索引i是从0开始构建
VinIndex(node);
for(let i=0;i<pindex.length-1;i++){
for(let j=i+1;j<pindex.length;j++){
if(pindex[i]>pindex[j]){
i=pindex.length-1;
j=pindex.length;
console.log("False")
}
if(i===pindex.length-2 && j===pindex.length-1){
console.log("True")
}
}
}