1980. Find Unique Binary String

Medium

30 Points

Array

Hash Table

String

Backtracking

Given an array of strings nums containing n unique binary strings each of length n, return a binary string of length n that does not appear in nums. If there are multiple answers, you may return any of them.

Examples

Example 1

Input: nums = ["01","10"] Output: "11" Explanation: "11" does not appear in nums. "00" would also be correct.

Example 2

Input: nums = ["00","01"] Output: "11" Explanation: "11" does not appear in nums. "10" would also be correct.

Example 3

Input: nums = ["111","011","001"] Output: "101" Explanation: "101" does not appear in nums. "000", "010", "100", and "110" would also be correct.

Constraints

n == nums.length
1 <= n <= 16
nums[i].length == n
nums[i] is either '0' or '1'.
All the strings of nums are unique.