Решение

class Solution {
    fun canMakeArithmeticProgression(arr: IntArray): Boolean {
        arr.sort()
        if (arr.size < 2) return true
        val diff = arr[1] - arr[0]
        for (i in 2 until arr.size) {
            if (arr[i] - arr[i - 1] != diff) return false
        }
        return true
    }
}