算法题目-21周-Maximum Level Sum of a Binary Tree

Given the root of a binary tree, the level of its root is 1, the level of its children is 2, and so on.

Return the smallest level X such that the sum of all the values of nodes at level X is maximal.

Example 1:

image

Input: [1,7,0,7,-8,null,null]
 
 
Output: 2
 Explanation:
 Level 1 sum = 1.
 Level 2 sum = 7 + 0 = 7.
 Level 3 sum = 7 + -8 = -1.
 So we return the level with the maximum sum which is level 2.
 
 
Note:
 
 
 
  
The number of nodes in the given tree is between 1 and 10^4.
 
  
-10^5 <= node.val <= 10^5
 
 
 
 
暴力解法：
 
 
        public int maxLevelSum(TreeNode root) {
        int[] sum = new int[40];
        int level = 0;
        check(root,sum,level);

        int retsum = 0;
        int retlevel = 0;

        for(int i=0;i
 
 
目前题目提交的人还是太少了，只有6千多通过，暴力都通过。
 Runtime: 3 ms, faster than 100.00% of Java online submissions for Maximum Level Sum of a Binary Tree.
 Memory Usage: 41.3 MB, less than 100.00% of Java online submissions for Maximum Level Sum of a Binary Tree.