【LeetCode】637. Average of Levels in Binary Tree

Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array.

Example 1:

Input:    3   / \  9  20    /  \   15   7Output: [3, 14.5, 11]Explanation:The average value of nodes on level 0 is 3,  on level 1 is 14.5, and on level 2 is 11. Hence return [3, 14.5, 11].

Note:

1. The range of node's value is in the range of 32-bit signed integer.

//深度优先算法var average = function(t,  i, sum, count) {        if (t == null)            return;        if (i < sum.length) {            sum.splice(i,1,sum[i] + t.val);            count.splice(i,1,count[i] + 1);        } else {            sum.push(1.0 * t.val);            count.push(1);        }        average(t.left, i + 1, sum, count);        average(t.right, i + 1, sum, count);    }var averageOfLevels = function(root) {    var count = new Array();    var res = new Array();    average(root, 0, res, count);    for (var i = 0; i < res.length; i++)        res.splice(i,1, res[i] / count[i]);    return res;}

//广度优先算法var averageOfLevels = function(root) {    var res=new Array();    var queue=new Array();    queue.push(root);    while(queue.length>0){        var sum=0,count=0;        var temp=new Array();        while(queue.length>0){            var n=queue.shift();            sum+= n.val;            count++;            if(n.left!=null){                temp.push(n.left);            }             if(n.right!=null){                temp.push(n.right);            }        }        queue=temp;        res.push(sum/count*1.0);    }    return res;};