[Leetcode] #112 Path Sum

Discription:

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.

Solution:

bool hasPathSum(TreeNode* root, int sum) {if (root == NULL) 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);}