LeetCode 3290: Maximum Multiplication Score

Explanation:

To solve this problem, we need to choose 4 indices from array b such that they are in increasing order and then calculate the score based on the given formula. We can achieve the maximum score by choosing the elements from b that have the highest positive or negative values.

To solve this problem efficiently, we can follow these steps:

1. Sort the array a in non-decreasing order.
2. Sort the array b in non-increasing order.
3. Initialize the maximum score as Integer.MIN_VALUE.
4. Iterate over all possible combinations of indices i0, i1, i2, and i3 in array b.
5. Calculate the score using the given formula and update the maximum score if the calculated score is greater.
6. Return the maximum score.

Time Complexity:

The time complexity of this approach is O(n^4), where n is the size of array b.

Space Complexity:

The space complexity is O(1) as we are using constant extra space.

:

class Solution {
    public int maxScore(int[] a, int[] b) {
        Arrays.sort(a);
        Arrays.sort(b);
        int maxScore = Integer.MIN_VALUE;
        for (int i = 0; i < b.length - 3; i++) {
            for (int j = i + 1; j < b.length - 2; j++) {
                for (int k = j + 1; k < b.length - 1; k++) {
                    for (int l = k + 1; l < b.length; l++) {
                        int score = a[0] * b[i] + a[1] * b[j] + a[2] * b[k] + a[3] * b[l];
                        maxScore = Math.max(maxScore, score);
                    }
                }
            }
        }
        return maxScore;
    }
}