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.
#include<iostream>
#include<vector>
using namespace std;
struct TreeNode {
int val;
TreeNode *left;
TreeNode *right;
TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
bool hasPathSum(TreeNode *root, int sum) {
if (root == NULL)
return false;
return judge(root, sum);
}
bool judge(TreeNode *root, int sum) {
if (root == NULL)
return false;
if (root->left==NULL&&root->right==NULL)
return sum-root->val==0? true : false;
return judge(root->left, sum - root->val) || judge(root->right, sum - root->val);
}