Open Cosen95 opened 4 years ago
不难看出,这是一道明显的可以用BFS(广度优先搜索)
解决的题目。
大概思路就是:
push
进结果数组中
/**
* Definition for a binary tree node.
* function TreeNode(val) {
* this.val = val;
* this.left = this.right = null;
* }
*/
/**
* @param {TreeNode} root
* @return {number[][]}
*/
var levelOrder = function(root) {
if (!root) return []
let res = [];
let queue = [root];
while (queue.length > 0) {
let len = queue.length;
let arr = [];
while (len) {
let node = queue.shift();
arr.push(node.val)
if (node.left) queue.push(node.left)
if (node.right) queue.push(node.right)
len--
}
res.push(arr)
}
return res
};
leetcode: https://leetcode-cn.com/problems/binary-tree-level-order-traversal/