LeetCode-in-Java
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:
1 <= nums.length <= 13-9 <= nums[i] <= 9
Solution
import java.util.ArrayList;
import java.util.List;
public class Solution {
public long maxStrength(int[] nums) {
List<Integer> filtered = new ArrayList<>();
long product = 1L;
boolean hasZero = false;
for (int num : nums) {
if (num == 0) {
hasZero = true;
continue;
}
filtered.add(num);
product *= num;
}
if (filtered.isEmpty()) {
return 0;
}
if (filtered.size() == 1 && filtered.get(0) <= 0) {
return hasZero ? 0 : filtered.get(0);
}
long result = product;
for (int num : nums) {
if (num == 0) {
continue;
}
result = Math.max(result, product / num);
}
return result;
}
}