Leetcode•Mar 10, 2026

Rotate Function

Hazrat Ali

Leetcode

Assume arrk to be an array obtained by rotating nums by k positions clock-wise. We define the rotation function F on nums as follow:

  • F(k) = 0 * arrk[0] + 1 * arrk[1] + ... + (n - 1) * arrk[n - 1].

Return the maximum value of F(0), F(1), ..., F(n-1).

The test cases are generated so that the answer fits in a 32-bit integer.

 

Example 1:

Input: nums = [4,3,2,6]
Output: 26
Explanation:
F(0) = (0 * 4) + (1 * 3) + (2 * 2) + (3 * 6) = 0 + 3 + 4 + 18 = 25
F(1) = (0 * 6) + (1 * 4) + (2 * 3) + (3 * 2) = 0 + 4 + 6 + 6 = 16
F(2) = (0 * 2) + (1 * 6) + (2 * 4) + (3 * 3) = 0 + 6 + 8 + 9 = 23
F(3) = (0 * 3) + (1 * 2) + (2 * 6) + (3 * 4) = 0 + 2 + 12 + 12 = 26
So the maximum value of F(0), F(1), F(2), F(3) is F(3) = 26.

Example 2:

Input: nums = [100]
Output: 0

Solution
var maxRotateFunction = function(nums) {
    const n = nums.length;

    let sum = 0;
    let F = 0;

    for (let i = 0; i < n; i++) {
        sum += nums[i];
        F += i * nums[i];
    }

    let result = F;

    for (let k = 1; k < n; k++) {
        F = F + sum - n * nums[n - k];
        result = Math.max(result, F);
    }

    return result;
};



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