C++ :

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <map>
using namespace std;
map<char,int> m1;
map<int,char> m2;
int n,a[505],cnt=0,ans=0;
char str[505];
int insert(char ch)
{
	if (m1.find(ch)==m1.end()) m1[ch]=++cnt;
	return m1[ch];
}
int main()
{
	scanf("%d%s",&n,str+1);
	for (int i=1;i<=n;i++)
		a[i]=insert(str[i]),m2[a[i]]=str[i];
	do{
		for (int i=1;i<=n;i++)
			if (i!=n) putchar(m2[a[i]]);
			else printf("%c\n",m2[a[i]]);
		ans++;
	}while (next_permutation(a+1,a+n+1));
	printf("%d\n",ans); 
	return 0;
}