题目:
题解:
- 简单的dfs
代码如下:
class Solution {
public:
int sumOfLeftLeaves(TreeNode* root) {
if(!root)return 0;
int sum=0;
dfs(root,sum);
return sum;
}
void dfs(TreeNode* root,int& sum)
{
if(root->left){
if(!root->left->left&&!root->left->right){
sum+=root->left->val;
}
else{
dfs(root->left,sum);
}
}
if(root->right){
dfs(root->right,sum);
}
}
};