1161. 最大层内元素和

绝地灬酷狼 2022-12-23 07:09 107阅读 0赞

# 题目来源 #

[1161. 最大层内元素和][1161.]

# 题目描述 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70_pic_center]

# 题目解析 #

/**
     * Definition for a binary tree node.
     * public class TreeNode {
     *     int val;
     *     TreeNode left;
     *     TreeNode right;
     *     TreeNode() {}
     *     TreeNode(int val) { this.val = val; }
     *     TreeNode(int val, TreeNode left, TreeNode right) {
     *         this.val = val;
     *         this.left = left;
     *         this.right = right;
     *     }
     * }
     */
    class Solution {
        
    public int maxLevelSum(TreeNode root) {
        
            if (root == null){
        
                return 0;
            }
            
            int maxSum = Integer.MIN_VALUE, currSum = 0;
            int maxDepth = 0, currDepth = 0;
            Queue<TreeNode> queue = new LinkedList<>();
            queue.offer(root);
            while (!queue.isEmpty()){
        
                int size = queue.size();
                currDepth++;
                currSum=0;
                for (int i = 0; i < size; i++){
        
                    TreeNode node = queue.poll();
                    currSum += node.val;
                    if (node.left != null){
        
                        queue.offer(node.left);
                    }
                    if (node.right != null){
        
                        queue.offer(node.right);
                    }
                }
                if (currSum > maxSum){
        
                    maxSum = currSum;
                    maxDepth = currDepth;
                }
            }
            return maxDepth;
        }
    }

![在这里插入图片描述][20201123191608612.png_pic_center]

[1161.]: https://leetcode-cn.com/problems/maximum-level-sum-of-a-binary-tree/submissions/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/b77ac15173a94e3f93ae00a8b467b3d2.png
[20201123191608612.png_pic_center]: https://img-blog.csdnimg.cn/20201123191608612.png#pic_center