LeetCode in Kotlin

2708. Maximum Strength of a Group

Medium

You are given a 0-indexed integer array nums representing the score of students in an exam. The teacher would like to form one non-empty group of students with maximal strength, where the strength of a group of students of indices i0, i1, i2, … , ik is defined as nums[i0] * nums[i1] * nums[i2] * ... * nums[ik].

Return the maximum strength of a group the teacher can create.

Example 1:

Input: nums = [3,-1,-5,2,5,-9]

Output: 1350

Explanation: One way to form a group of maximal strength is to group the students at indices [0,2,3,4,5]. Their strength is 3 * (-5) * 2 * 5 * (-9) = 1350, which we can show is optimal.

Example 2:

Input: nums = [-4,-5,-4]

Output: 20

Explanation: Group the students at indices [0, 1] . Then, we’ll have a resulting strength of 20. We cannot achieve greater strength.

Constraints:

Solution

class Solution {
    fun maxStrength(nums: IntArray): Long {
        val filtered = mutableListOf<Int>()
        var product = 1L
        var hasZero = false
        for (num in nums) {
            if (num == 0) {
                hasZero = true
                continue
            }
            filtered.add(num)
            product *= num.toLong()
        }
        if (filtered.isEmpty()) return 0
        if (filtered.size == 1 && filtered[0] <= 0) return if (hasZero) 0 else filtered[0].toLong()
        var result = product
        for (num in nums) {
            if (num == 0) continue
            result = result.coerceAtLeast(product / num.toLong())
        }
        return result
    }
}