Path Sum -- Leetcode

Question:

Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

Answer:

class Solution {

public:

    bool hasPathSum(TreeNode *root, int sum) {

        if(!root)return false;

        else if(!root->left&&!root->right&&root->val==sum) return true;

        else{

            if(hasPathSum(root->left,sum-root->val)||hasPathSum(root->right,sum-root->val)){

                return true;

            }

            else

               return false;

        }

    }

};