n number of children are sitting, only one person sitting right, everyone else took the wrong circumstances How many?

n number of children are sitting, only one person sitting right, everyone else took the wrong circumstances How many?

 

#include <iostream>

using namespace std;

int nums[66];

int func(int n)
{
    nums[2] = 1;
    for (int i = 3; i <= n; i++)
    {
        nums[i] = (i - 1) * (nums[i-1] + nums[i-2]);
    }
    return nums[n];
}

int main()
{
    int n;
    cin >> n;
    cout << n*func(n-1) << endl;
 system("pause");
    return 0;
}