396. Rotate Function

/**
 * Problem: LeetCode 396 - Rotate Function
 * Difficulty: Medium
 * Language: Java
 * Author: CodeByTushu
 */
class Solution {
    public int maxRotateFunction(int[] nums) {
        int n = nums.length;
        long totalSum = 0;
        long currentF = 0;

        for (int i = 0; i < n; i++) {
            totalSum += nums[i];
            currentF += (long) i * nums[i];
        }

        long maxF = currentF;

        for (int k = 1; k < n; k++) {
            currentF += totalSum - (long) n * nums[n - k];
            maxF = Math.max(maxF, currentF);
        }

        return (int) maxF;
    }
}

"""
Problem: LeetCode 396 - Rotate Function
Difficulty: Medium
Language: Python
Author: CodeByTushu
"""
from typing import List

class Solution:
    def maxRotateFunction(self, nums: List[int]) -> int:
        n = len(nums)
        total_sum = sum(nums)
        current_f = sum(i * val for i, val in enumerate(nums))
        max_f = current_f

        for k in range(1, n):
            current_f += total_sum - n * nums[n - k]
            if current_f > max_f:
                max_f = current_f

        return max_f

/**
 * Problem: LeetCode 396 - Rotate Function
 * Difficulty: Medium
 * Language: C++
 * Author: CodeByTushu
 */
#include <vector>
#include <algorithm>
#include <numeric>

using namespace std;

/**
 * Problem: LeetCode 396 - Rotate Function
 * Difficulty: Medium
 * Language: C++
 * Author: CodeByTushu
 */
class Solution {
public:
    int maxRotateFunction(vector<int>& nums) {
        int n = nums.size();
        long long totalSum = 0;
        long long currentF = 0;

        for (int i = 0; i < n; i++) {
            totalSum += nums[i];
            currentF += 1LL * i * nums[i];
        }

        long long maxF = currentF;

        for (int k = 1; k < n; k++) {
            currentF += totalSum - 1LL * n * nums[n - k];
            maxF = max(maxF, currentF);
        }

        return static_cast<int>(maxF);
    }
};

/**
 * Problem: LeetCode 396 - Rotate Function
 * Difficulty: Medium
 * Language: JavaScript
 * Author: CodeByTushu
 */
var maxRotateFunction = function(nums) {
    const n = nums.length;
    let totalSum = 0;
    let currentF = 0;

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

    let maxF = currentF;

    for (let k = 1; k < n; k++) {
        currentF += totalSum - n * nums[n - k];
        if (currentF > maxF) {
            maxF = currentF;
        }
    }

    return maxF;
};