5 / 4 8 / / 11 13 4 / 7 2 1

/** * Definition for binary tree * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { boolean flag=false; public boolean hasPathSum(TreeNode root, int sum) { if(root==null) return flag; isTrue(root,sum); return flag; } public void isTrue(TreeNode root, int sum){ if(root==null) return; if(root.right==null && root.left==null && sum-root.val==0) flag=true; else { isTrue(root.left,sum-root.val); isTrue(root.right,sum-root.val); } } }