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.
public class Solution { public boolean hasPathSum(TreeNode root, int sum) { if(root == null) return false; if(sum == root.val&& root.left == null && root.right == null){ return true; }else{ return hasPathSum(root.left, sum - root.val) ||hasPathSum(root.right,sum - root.val); } } }
mistake: when root.val == sum make sure left is null and right is null