C program to find nCr using function.

C program to find nCr using function.

#include<stdio.h>

long factorial(int);

long find_ncr(int, int);

long find_npr(int, int);

main()

{

   int n, r;

   long ncr, npr;

   printf("Enter the value of n and r\n");

   scanf("%d%d",&n,&r);

   ncr = find_ncr(n, r);

   npr = find_npr(n, r);

   printf("%dC%d = %ld\n", n, r, ncr);

   printf("%dP%d = %ld\n", n, r, npr);

   return 0;

}

long find_ncr(int n, int r)

{

   long result;

   result = factorial(n)/(factorial(r)*factorial(n-r));

   return result;

}

long find_npr(int n, int r)

{

   long result;

   result = factorial(n)/factorial(n-r);

   return result;

}

long factorial(int n)

{

   int c;

   long result = 1;

   for( c = 1 ; c <= n ; c++ )

      result = result*c;

   return ( result );

}