A. Puzzles Solution

#include <iostream>

#include <algorithm>

using namespace std;

int main()

{

    int n, m, f[1000];

    cin >> n >> m;

    for (int i = 0; i < m; ++i)

    {

        cin >> f[i];

    }

    sort(f, f + m);

    int least = f[n-1] - f[0];

    for (int i = 1; i <= m - n; ++i)

    {

        if (f[i+n-1] - f[i] < least)

        {

            least = f[i+n-1] - f[i];

        }

    }

    cout << least << endl;

    return 0;

}