How t write Recursive C program to find Binomial coefficient?

#include<stdio.h>

int fact(int);

void main()

{

int n,r,f;

printf("enter value for n & r\n");

scanf("%d%d",&n,&r);

if(n<r)

printf("invalid input");

else

f=fact(n)/(fact(n-r)*fact(r));

printf("binomial coefficient=%d",f);

}

int fact(int x)

{

if(x>1)

return x*fact(x-1);

else

return 1;

}