Robotic moves

A robot's initial position is $(0,0)$ and it can only move along X-axis. It has $N$ moves to make and in each move, it will select one of the following options:

1. Go to $(X-1,0)$ from $(X,0)$
2. Go to $(X+1,0)$ from $(X,0)$
3. Remain at its current position

Your task is to calculate $\sum (abs(X)+abs(Y))$ for all reachable $(X, Y)$.

Note: Here, $abs$ denotes the absolute value.

Example

Input: n = 1
Output: 2

Approach

Java

public class RoboticMoves {
    public static void main(String args[]) throws Exception {
      
        int n = 1;
        long ans = ((long) n) * (n + 1);
        System.out.println(ans);
    }

}

C++

#include <bits/stdc++.h>
using namespace std;

long roboticMoves(long n)
{
    long ans = n * (n + 1);
    return ans;
}
int main()
{
    long n = 1;
    cout << roboticMoves(n) << "\n";

    return 0;
}