MyLeetcode/cpp_solutions/1161.cpp at main · Kaminyou/MyLeetcode · GitHub

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/**
 * 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 maxValue = INT_MIN;
        int maxValueLevel = 0;
        int currentLevel = 1;
        queue<TreeNode*> q;
        if (root) q.push(root);
        while (!q.empty()) {
            int n = q.size();
            int sum = 0;
            for (int i = 0; i < n; ++i) {
                TreeNode* node = q.front();
                q.pop();
                sum += node->val;
                if (node->left) q.push(node->left);
                if (node->right) q.push(node->right);
            }
            if (sum > maxValue) {
                maxValue = sum;
                maxValueLevel = currentLevel;
            }
            currentLevel++;
        }
        return maxValueLevel;
    }
};