【LeetCode】112. Path Sum

问题描述

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.

For example:
Given the below binary tree and sum = 22,

              5
             / \
            4   8
           /   / \
          11  13  4
         /  \      \
        7    2      1

return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.

代码

class Solution {
public:
	
	bool hasPathSum(TreeNode* root, int sum) {
		if(root==0) return false;
		if(root->val==sum&&root->right==0&&root->left==0) return true;
    	sum -= root->val;
    	return hasPathSum(root->left, sum)||hasPathSum(root->right,sum);
    }
};