【Leetcode】404. Sum of Left Leaves

404. Sum of Left Leaves

【题目】中文版  英文版

 /**
  * Definition for a binary tree node.
  * struct TreeNode {
  *     int val;
  *     TreeNode *left;
  *     TreeNode *right;
  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
  * };
  */
 class Solution
 {
 public:
     int sumOfLeftLeaves(TreeNode* root)
     {
         int res = ;
         solute(root, res, false);
         return res;
     }

     void solute(TreeNode *root, int &sum, bool flag)
     {
         if(root == nullptr)
             return;
         if(!root->left && !root->right)
         {
             if(flag == true)
                 sum += root->val;
             return;
         }
         solute(root->left, sum, true);
         solute(root->right, sum, false);
         return;
     }
 };