标签：style blog color io ar for sp div on
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.
1 /** 2 * Definition for binary tree 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */ 10 public class Solution { 11 public boolean hasPathSum(TreeNode root, int sum) { 12 if (root == null) { 13 return false; 14 } 15 if (root.val==sum && root.left==null && root.right==null) { 16 return true; 17 } 18 19 return hasPathSum(root.left, sum-root.val) || hasPathSum(root.right, sum-root.val); 20 } 21 }
标签：style blog color io ar for sp div on
原文地址：http://www.cnblogs.com/birdhack/p/4039074.html
