1302. Deepest Leaves Sum

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1302. Deepest Leaves Sum

Description

Given the root of a binary tree, return the sum of values of its deepest leaves.

Example 1:

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Input: root = [1,2,3,4,5,null,6,7,null,null,null,null,8]
Output: 15

Example 2:

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Input: root = [6,7,8,2,7,1,3,9,null,1,4,null,null,null,5]
Output: 19

Constraints:

  • The number of nodes in the tree is in the range [1, 10^4].
  • 1 <= Node.val <= 100

Hints/Notes

  • binary tree

Solution

Language: C++

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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 deepestLeavesSum(TreeNode* root) {
        int res = 0;
        queue<TreeNode*> q;
        if (root)
            q.push(root);
        while (!q.empty()) {
            int n = q.size(), sum = 0;
            for (int i = 0; i < n; i++) {
                TreeNode* cur = q.front();
                q.pop();
                sum += cur->val;
                if (cur->left)
                    q.push(cur->left);
                if (cur->right)
                    q.push(cur->right);
            }
            res = sum;
        }
        return res;
    }
};