112. Path Sum.cpp

//
//  112. Path Sum.cpp
//  leetcode
//
//  Created by R Z on 2017/10/23.
//  Copyright © 2017年 R Z. All rights reserved.
//

#include <stdio.h>
/**
 * 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) return false;
        if(root->val == sum && root->left == NULL && root->right==NULL) return true;
        return hasPathSum(root->left, sum-root->val) || hasPathSum(root->right, sum - root->val);
    }
};