学步园

深搜 递归

#include <iostream>
using namespace std;

struct TreeNode 
{
 int val;
 TreeNode *left, *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 && !root->right)
			return true;
		else
 			return hasPathSum(root->left, sum - root->val) || hasPathSum(root->right, sum - root->val);		
    }
};

int main(void)
{
	TreeNode *root = new TreeNode(5);
	TreeNode *node1 = new TreeNode(4);  root->left = node1;
	TreeNode *node2 = new TreeNode(8);	root->right = node2;
	TreeNode *node3 = new TreeNode(11);	node1->left = node3;
	TreeNode *node4 = new TreeNode(13);	node2->left = node4;
	TreeNode *node5 = new TreeNode(4);	node2->right = node5;
	TreeNode *node6 = new TreeNode(7);	node3->left = node6;
	TreeNode *node7 = new TreeNode(2);	node3->right = node7;
	TreeNode *node8 = new TreeNode(1);	node5->right = node8;
	
	Solution s;
	
	cout << s.hasPathSum(root, 22) << endl;
	
	return 0;
}