C++primer plus第六版课后编程题答案7.4

#include <iostream>
using namespace std;
typedef unsigned int uint;
long double probability(uint,uint);
void main74()
{
long double fildNumber=probability(47,5);
long double specialNumber=probability(27,1);
cout<<"probalility is:"<<fildNumber*specialNumber<<endl;
getchar();
getchar();

}

long double probability(uint numbers,uint picks)
{
long double result=1.0;
long double n;
uint p;
for(n=numbers,p=picks;p>0;p--,n--)
result=result*n/p;
return result;

}