LeetCode/kt/split-array-into-consecutive-subsequences.kt

class Solution {
    private fun getFrequencies(nums: IntArray): MutableMap<Int, Int> {
        val freqs = mutableMapOf<Int, Int>()

        nums.forEach {
            freqs[it] = 1 + freqs.getOrDefault(it, 0)
        }

        return freqs
    }

    fun isPossible(nums: IntArray): Boolean {
        val frequencies = getFrequencies(nums)
        val sortedNumbers = frequencies.keys.toList().sorted()

        sortedNumbers.forEach {
            while (frequencies[it]!! > 0) {
                var last = 0
                var j = it
                var k = 0

                while (frequencies.getOrDefault(j, 0) >= last) {
                    last = frequencies[j]!!
                    frequencies[j] = frequencies[j]!! - 1

                    j++
                    k++
                }
                if (k < 3) {
                    return false
                }
            }
        }

        return true
    }
}