Problem:
Score : 100 points

Problem Statement

We have an N \times N square grid.

We will paint each square in the grid either black or white.

If we paint exactly A squares white, how many squares will be painted black?

Constraints

1 \leq N \leq 100

0 \leq A \leq N^2

Inputs

Input is given from Standard Input in the following format:

N
A

Outputs

Print the number of squares that will be painted black.

Sample Input 1

3
4

Sample Output 1

5

There are nine squares in a 3 \times 3 square grid.
Four of them will be painted white, so the remaining five squares will be painted black.

Sample Input 2

19
100

Sample Output 2

261

Sample Input 3

10
0

Sample Output 3

100

As zero squares will be painted white, all the squares will be painted black.

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    int n, k, i, ans = 0, dist1, dist2, j = 0;
    cin >> n >> k;
    int x[n];
    for (i  = 0; i < n; ++i)
    {
        cin >> x[i];
    }
    for (i = 0; i < n; ++i)
    {
            dist1 = 2 * x[i];
            dist2 = abs(x[i] - k) * 2;
            ans += min(dist1, dist2);
    }
    cout << ans;
    return 0;
}