字典序全排列

//字典序全排列.cpp
#include<iostream>
#include<string>
using namespace std;
#define M 100
int count;
void prin(int *a,int m)
{
int i;
cout<<count++<<": ";
for(i=0;i<m-1;i++)
cout<<a[i]<<" ";
cout<<a[m-1]<<endl;
}
void genperm(int *a,int n,int &index)
{
int i,j,k,t,tmp;
if(a[index]==n-index)
index++;
prin(a,n);
for(j=n-2;j>=0;j--)
if(a[j]<a[j+1])
break;
for(k=n-1;k>=0;k--)
if(a[k]>a[j])
break;
tmp=a[j],a[j]=a[k],a[k]=tmp;
for(i=j+1,t=n-1;i<=t;i++,j--)
tmp=a[i],a[i]=a[t],a[t]=tmp;
}
void genallperm(int *a,int n)
{
int index;
for(index=0;index<n;index++)
a[index]=index+1;
index=0;
while(index<n-1)
genperm(a,n,index);
}
int main()
{
int n,t,cnt=0,a[M];
while(cin>>n)
{
count=1;
if(n==0)
break;
cout<<"Case "<<++cnt<<" :n= "<<n<<endl;
genallperm(a,n);
cout<<endl;
}
return 0;
}