Calculate nPr & nCr

C++ Program to calculate nPr & nCr. This program calculates the value of nCr and nPr. The values of n and r are input by user. We have used 3 functions : 'npr' for calculating nPr , 'ncr' for calculating nCr , factorial to calculate factorial. nPr is calculated by the formula nPr = factorial(n)/factorial(n-r)
, nCr by factorial(n)/(factorial(r)*factorial(n-r)).  The values are calculated by these functions and factorial by 'factorial'. The results are printed using cout.

Source Code:-

#include<iostream.h>
#include<conio.h>
long fnpr(int, int);
long fncr(int, int);
long factorial(int);
void main()
{
 int n, r;
 long ncr, npr;
 clrscr();
 cout<<"Calculate nCr & nPr by-Tarun Rawat\n";
 cout<<"\nEnter the value of n : ";
 cin>>n;
 cout<<"Enter the value of r : ";
 cin>>r;
 ncr=fncr(n,r);
 npr=fnpr(n,r);
 cout<<"\nValue of "<<n<<"C"<<r<<" = "<<ncr;
 cout<<"\nValue of "n<<"P"<<r<<" = "<<npr;
 getch();
}
long fnpr(int n,int r)
{
 long value;
 value=factorial(n)/factorial(n-r);
 return value;
}
long fncr(int n,int r)
{
 long value;
 value=factorial(n)/(factorial(r)*factorial(n-r));
 return value;
}
long factorial(int n)
{
 if(n==0)
   return 1;
 else
 {
 return(n*factorial(n-1));
 }
}