LeetCode/kt/take-k-of-each-character-from-left-and-right.kt

class Solution {
    fun takeCharacters(
        s: String,
        k: Int,
    ): Int {
        val counters = IntArray(3)

        // Get the frequencies
        for (c in s) {
            counters[c - 'a'] += 1
        }

        // Check for at least ‹k› characters
        if (counters.any { it < k }) {
            return -1
        }

        var l = 0
        var maxWindow = 0

        val window = IntArray(3)
        for (r in s.indices) {
            window[s[r] - 'a'] += 1

            while (
                l <= r &&
                counters.zip(window).any { (c, w) -> c - w < k }
            ) {
                window[s[l] - 'a'] -= 1
                l += 1
            }

            maxWindow = listOf(maxWindow, r - l + 1).max()
        }

        return s.length - maxWindow
    }
}