Today is Sunday, I gonna review the tasks I've done this week, and finish today's leetcode's April LeetCoding Challenge with cpp.

April LeetCoding Challenge 11

Description

Deepest Leaves Sum

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

Example 1:

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

Example 2:

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, 104].
• 1 <= Node.val <= 100

Solution

class Solution {
  int sum = 0;
  int height = 0;
  void solve(TreeNode *root, int level) {
    if(!root) return;
    if(level > height) {
      sum = 0;
      height = level;
    }
    sum += (level == height) * root->val;
    solve(root->left, level + 1);
    solve(root->right, level + 1);
  }
public:
  int deepestLeavesSum(TreeNode* root) {
    solve(root, 0);
    return sum;
  }
};