✅Max permute (Contest)

Max permute (Contest) easy Time Limit: 2 sec Memory Limit: 128000 k

Problem Statement :

Given N. You have to construct an array Arr of N integers such that it contains integers from 1 to N and each integer comes at max once. The goodness of the array is summation (Arr[i]%i) for i from 1 to N. You have to construct array with maximum goodness. As N can be huge you only have to report the maximum goodness and not the array. Input Input contains a single integer N.

Constraints: 1 <= N <= 1000000000 Output Print the maximum goodness possible. Example Sample Input 2

Sample Output 1

Explanation: Array constructed will be [2, 1] goodness = 1%2 + 2%1 = 1

Sample Input 5

Sample Output 10

Explanation: Array constructed will be [1, 3, 4, 5, 2] goodness = 1%1 + 2%3 + 3%4 + 4%5 + 5%2 = 10

link:https://my.newtonschool.co/playground/code/0o9a7cnxz89r/

```java
import java.io.*; // for handling input/output
import java.util.*; // contains Collections framework

// don't change the name of this class
// you can add inner classes if needed
class Main {
    public static void main (String[] args) {
        Scanner inp = new Scanner(System.in);
        long n = inp.nextLong();
        long sum = 0;
        sum = ((n-1)*n)/2;
        System.out.print(sum);
    }
}
```