class Solution {
public:
int sumOfLeftLeaves(TreeNode* root) {
if (!root) return 0;
if (root>left && !root>left>left && !root>left>right) return root>left>val + sumOfLeftLeaves(root>right);
return sumOfLeftLeaves(root>left) + sumOfLeftLeaves(root>right);
}
};
3line c++ solution


@luckyever619 No node is present here,so sum of left leaf of this noexistent node is 0.