112. Path Sum

/** * 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:    bool hasPathSum(TreeNode* root, int sum) {        if(root == NULL){            return false;        }        else if (root->right == NULL && root->left == NULL && root->val == sum)        {              return true;        }        else {            return hasPathSum(root->left, sum-root->val) || hasPathSum(root->right, sum - root->val);        }           }};