全排列函数

void perm (int A[], int n, int k)
{
if (k == n) print( A , n );
else 
   for (int i = k;i < n; i++)
   {
    swap(A[i],A[k]);
    perm (A,n,k+1);
    swap(A[i],A[k]);
   }
}

//下面有验证代码

#include <fstream>
#include <iostream>

using namespace std;
ofstream outfile ("out.txt");

int A[100];

void print ( int A[] , int n)
{
for (int i = 1 ; i < n; i++)
{
   cout<<A[i]<<" "; 
   outfile<<A[i]<<" "; 
}
outfile<<endl;
cout<<endl;
}


void perm (int A[], int n, int k)
{
if (k == n) print( A , n );
else 
   for (int i = k;i < n; i++)
   {
    swap(A[i],A[k]);
    perm (A,n,k+1);
    swap(A[i],A[k]);
   }
}

int main ()
{

    for (int i = 0; i < 100; i++)
    A[i]=i;
int n;
cout<<"请输入排列数的个数："<<endl;
cin >> n;
perm (A , n+1, 1);
return 0;
}