README_EN.md

1551. Minimum Operations to Make Array Equal

中文文档

Description

You have an array arr of length n where arr[i] = (2 * i) + 1 for all valid values of i (i.e., 0 <= i < n).

In one operation, you can select two indices x and y where 0 <= x, y < n and subtract 1 from arr[x] and add 1 to arr[y] (i.e., perform arr[x] -=1 and arr[y] += 1). The goal is to make all the elements of the array equal. It is guaranteed that all the elements of the array can be made equal using some operations.

Given an integer n, the length of the array, return the minimum number of operations needed to make all the elements of arr equal.

 

Example 1:

Input: n = 3
Output: 2
Explanation: arr = [1, 3, 5]
First operation choose x = 2 and y = 0, this leads arr to be [2, 3, 4]
In the second operation choose x = 2 and y = 0 again, thus arr = [3, 3, 3].

Example 2:

Input: n = 6
Output: 9

 

Constraints:

• 1 <= n <= 104

Solutions

Python3

class Solution:
    def minOperations(self, n: int) -> int:
        ans = 0
        for i in range(n >> 1):
            ans += n - (2 * i + 1)
        return ans

Java

class Solution {
    public int minOperations(int n) {
        int ans = 0;
        for (int i = 0; i < (n >> 1); i++) {
            ans += (n - (2 * i + 1));
        }
        return ans;
    }
}

C++

class Solution {
public:
    int minOperations(int n) {
        int ans = 0;
        for (int i = 0; i < (n >> 1); ++i) ans += (n - (2 * i + 1));
        return ans;
    }
};

Go

func minOperations(n int) int {
	ans := 0
	for i := 0; i < (n >> 1); i++ {
		ans += (n - (2*i + 1))
	}
	return ans
}

...