C++primer plus第六版课后编程题答案7.4

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;     
     
     
}