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:
1 <= nums.length <= 13
-9 <= nums[i] <= 9
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
}
}