C + + full arrangement and combinatorial algorithm (recursive)

Full arrangement:

The array to be arranged is a[n], which is divided into 0~s-1 and s~n-1 at any time.

Among them, the 0~s-1 is the interval that has been chosen, s~n-1 is the interval to be chosen, the exchange of a number of s~n-1 with s for each choice

#include <iostream>
using namespace std;

void swap (int *a, int i, int j)
{
	int tmp = a[i];
	A[i] =  a[j];
	A[J] = tmp;
}

0~s-1, s~n-1
void perm (int *a, int s, int n)
{
	if (s >= N)
	{for
		(int i = 0; i < n; i++) 
  {
			cout << a[i] << ",";
		}
		cout << Endl;
	}
	else
	{for
		(int i = s; i < n; i++)
		{
			Swap (a, S, i);
			Perm (A, s+1, n);
			Swap (A, S, i);


}} int main ()
{
	int n;
	CIN >> N;
	int a[100];
	for (int i = 0; i < n; i++)
	{
		cin >> a[i];
	}
	Perm (A, 0, N);
	return 0;
}

Combination algorithm:

All combinations of size m are found from array a[n with size n]

recursive function comp (int *a, int h, int k, int *sub) represents the selection of K in the number of the first h in array A, because you can choose to k-1 the next recursive recursion, so the range of this selection is a[i], where k-1<= i <= h-1, and a[ I] copied to the selected sub[k-1],

And the next recursive comp (A, I, k-1, sub) represents the selection of k-1 in the first number of the array a

#include <iostream>
using namespace std;

int n;
int m;
int num = 0;

void comb (int *a, int h, int k, int *sub)
{
	if (k = = 0)
	{for
		(int i = 0; i < m; i++)
		{
			cout ;< Sub[i] << ",";
		}
		cout << Endl;
		num + +;
	}
	else
	{for
		(int i = h-1 i >= k-1; i--)
		{
			sub[k-1] = a[i];
			Comb (A, I, k-1, sub);

}} int main ()
{
	int n;
	CIN >> n >> m;
	int a[100], sub[100];
	for (int i = 0; i < n; i++)
	{
		cin >> a[i];
	}
	Comb (A, n, M, sub);
	cout << num << endl;
	return 0;
}