BiruLyu
5/30/2017 - 2:33 AM

## 112. Path Sum(#1).java

``````/**
* Definition for a binary tree node.
* public class TreeNode {
*     int val;
*     TreeNode left;
*     TreeNode right;
*     TreeNode(int x) { val = x; }
* }
*/
class Solution {
public boolean hasPathSum(TreeNode root, int sum) {
if (root == null) return false;
if (root.left == null && root.right == null) return sum == root.val;
boolean left = false, right = false;
if (root.left != null) left =  hasPathSum(root.left, sum - root.val);
if (root.right != null) right = hasPathSum(root.right, sum - root.val);
return left || right;
}
}``````
``````/**
* Definition for a binary tree node.
* public class TreeNode {
*     int val;
*     TreeNode left;
*     TreeNode right;
*     TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public boolean hasPathSum(TreeNode root, int sum) {
if( root == null) return false;
if( root.left == null && root.right == null) return (root.val == sum);
if( root.left == null) return hasPathSum(root.right, sum - root.val);
if( root.right == null) return hasPathSum(root.left, sum - root.val);
return hasPathSum(root.right, sum - root.val) || hasPathSum(root.left, sum - root.val);
}
}``````