// Package q1980 implements a solution for https://leetcode.com/problems/find-unique-binary-string/
package q1980

import "slices"

func toNumber(s string) int {
	ret := 0
	for i := range len(s) {
		ret = ret<<1 + int(s[i]-'0')
	}
	return ret
}

func fromNumber(n, length int) string {
	buf := make([]byte, length)
	for i := range length {
		buf[i] = byte(n&1) + '0'
		n >>= 1
	}
	slices.Reverse(buf)
	return string(buf)
}

func findDifferentBinaryString(nums []string) string {
	slices.Sort(nums)
	last := -1
	for i := range nums {
		num := toNumber(nums[i])
		if num > last+1 {
			break
		}
		last = num
	}
	return fromNumber(last+1, len(nums[0]))
}

var _ = findDifferentBinaryString