【Leetcode】404. Sum of Left Leaves

404. Sum of Left Leaves

【题目】中文版  英文版

 1 /**
 2  * Definition for a binary tree node.
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution 
11 {
12 public:
13     int sumOfLeftLeaves(TreeNode* root) 
14     {
15         int res = 0;
16         solute(root, res, false);
17         return res;
18     }
19     
20     void solute(TreeNode *root, int &sum, bool flag)
21     {
22         if(root == nullptr)
23             return;
24         if(!root->left && !root->right)
25         {
26             if(flag == true)
27                 sum += root->val;
28             return;
29         }
30         solute(root->left, sum, true);
31         solute(root->right, sum, false);
32         return;
33     }
34 };