LeetCode/kt/partition-labels.kt

class Solution {
    fun partitionLabels(s: String): List<Int> {
        val (firstIndex, lastIndex) = IntArray(26) to IntArray(26)
        s.withIndex().forEach { (index, c) ->
            lastIndex[c - 'a'] = index
        }

        val sizes = mutableListOf<Int>()

        var (start, end) = 0 to 0
        s.withIndex().forEach { (i, c) ->
            val idx = c - 'a'
            if (firstIndex[idx] == 0) {
                firstIndex[idx] = i
            }

            if (end < firstIndex[idx]) {
                sizes.add(end - start + 1)
                start = i
                end = i
            }

            end = maxOf(end, lastIndex[idx])
        }

        if (end - start + 1 > 0) {
            sizes.add(end - start + 1)
        }

        return sizes
    }
}