[LeetCode] Path Sum
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.
问题描述：给定一个二叉树和一个和值，判断这个二叉树是否有一条从根节点到叶节点的路径，该路径上的节点的值的和等于给定的和值。
看到二叉树的题目，就想到了递归，这道题也可以先看看递归方法。
如果到了叶节点，它的值和给定的值相等，那么就存在一条路径。然后遍历左右子树。
class Solution {
public:
bool hasPathSum(TreeNode *root, int sum) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.
if(root == NULL)
return false;
else if(root->left == NULL && root->right == NULL && sum == root->val)
return true;
return hasPathSum(root->left, sum-(root->val)) || hasPathSum(root->right, sum-(root->val));
}
};
补充：软件开发 , C++ ,
