<-E 404> Sum of Left Leaves
/**
* 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 sumOfLeftLeaves(TreeNode* root) {
if(root == nullptr) return 0;
int sum = 0;
if(root ->left != nullptr && root->left-> left == nullptr && root->left->right == nullptr)
sum += root->left->val;
return sum + sumOfLeftLeaves(root->left) + sumOfLeftLeaves(root->right);
}
};