LeetCode in Kotlin

1461. Check If a String Contains All Binary Codes of Size K

Medium

Given a binary string s and an integer k, return true if every binary code of length k is a substring of s. Otherwise, return false.

Example 1:

Input: s = “00110110”, k = 2

Output: true

Explanation: The binary codes of length 2 are “00”, “01”, “10” and “11”. They can be all found as substrings at indices 0, 1, 3 and 2 respectively.

Example 2:

Input: s = “0110”, k = 1

Output: true

Explanation: The binary codes of length 1 are “0” and “1”, it is clear that both exist as a substring.

Example 3:

Input: s = “0110”, k = 2

Output: false

Explanation: The binary code “00” is of length 2 and does not exist in the array.

Constraints:

Solution

class Solution {
    fun hasAllCodes(s: String, k: Int): Boolean {
        val total = Math.pow(2.0, k.toDouble()).toInt()
        var start = 0
        var end = start + k
        val st: MutableSet<String> = HashSet()
        while (end <= s.length) {
            val sbStr = s.substring(start, end)
            st.add(sbStr)
            if (st.size == total) {
                return true
            }
            start++
            end++
        }
        return false
    }
}