#include <iostream.h>
main()
{
double long m,n;
cout<<"请输入阶乘数";
cin>>n;
m=n;
if((n==1)||(n==0))
{
cout<<n<<"的阶乘是1"<<endl;
cout<<"请输入阶乘数";
cin>>n;
}
while (n>0)
{

for(int i=n;i>1;i--)
m=m*(i-1);
cout<<n<<"的阶乘是"<<m<<endl;
cout<<"请输入阶乘数";
cin>>n;
m=n;
if(n<0)
{
cout<<"你TMD搞笑"<<endl;
break;
}
}
}

#include <iostream.h>
main()
{
double long n,m;
do
{
cout<<"请输入阶乘数";
cin>>n; m=1;
if(n==0)cout<<"0的阶乘是1"<<endl；
else if(n>0)
{
for(;n>0;n--)
m*=n;
cout<<n<<"的阶乘是"<<m<<endl;
}
if(n<0)
{
cout<<"你**搞笑"<<endl;
break;
}
}while(n>=0);
}

#include <iostream.h>
main()
{
double long n,m,temp;
do
{
cout<<"请输入阶乘数";
cin>>n; temp=n;m=1;
if(n==0)cout<<"0的阶乘是1"<<endl；
else if(n>0)
{
for(;n>0;n--)
m*=n;
cout<<temp<<"的阶乘是"<<m<<endl;
}
if(n<0)
{
cout<<"你**搞笑"<<endl;
break;
}
}while(n>=0);
}