365天挑战LeetCode1000题——Day 044 最大层内元素和 层次遍历

1161. 最大层内元素和

代码实现（自解）

/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode() : val(0), left(nullptr), right(nullptr) {} * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {} * TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {} * }; */
class Solution {
    
public:
    int maxLevelSum(TreeNode* root) {
    
        int maxSum = INT_MIN, maxLevel = 0;
        queue<TreeNode*> _queue;
        int curSum = 0, curLevel = 0, sz = 0;
        TreeNode* curNode = NULL;
        _queue.push(root);
        while (!_queue.empty()) {
    
            sz = _queue.size();
            curSum = 0;
            curLevel++;
            while (sz--) {
    
                curNode = _queue.front();
                _queue.pop();
                curSum += curNode->val;
                if (curNode->left) _queue.push(curNode->left);
                if (curNode->right) _queue.push(curNode->right);
            }
            if (curSum > maxSum) {
    
                maxSum = curSum;
                maxLevel = curLevel;
            }
        }
        return maxLevel;
    }
};