Sum Root to Leaf Numbers

Question

Here is the problem (It's on LeetCode)

Here is my code:

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    private static List<String> list = new LinkedList<String>();
    public int sumNumbers(TreeNode root) {
        serachBinaryTreeRecursion(root, "");
        int result = 0;
        for(String i : list){
            result += Integer.valueOf(i);
        }
        return result;
    }

    public void serachBinaryTreeRecursion(TreeNode root, String path) {
        if (root == null) {
            return;
        }
        if (root.left != null) {
            serachBinaryTreeRecursion(root.left, path + String.valueOf(root.val));
        }
        if (root.right != null) {
            serachBinaryTreeRecursion(root.right, path + String.valueOf(root.val));
        }
        if (root.left == null && root.right == null) {
            list.add((path + String.valueOf(root.val)));
        }
    }
}

When I submit this,it reports errors.

I test on eclipse,the result is correct.

What's wrong with my code?

Answer 1

Why are you doing String.valueOf(root.val) ? That is converting your int variable to string and adding 0 to 1 as string, not as integer, hence wrong result.

Answer 2

For [0, 1] you seem to have constructed a tree 1 -> (0, -) instead of 0 -> (-, 1) . Hence 10 instead of 1. So the algorithm did function.

Operation successful, patient dead.

(Please no "serach..." too.)