/*  Fun‡”es - Introdu‡„o.
		C lculo combinat˘rio - I.
		PP, 96.12                                                       */

#include <stdio.h>

long int fact (long int);

main()
{   int n, p;
	int nf, pf, nmpf;

	printf("C lculo de Combina‡”es de n p a p\n");
	printf("Introduza o valor de n :"); scanf("%d", &n);
	printf("Introduza o valor de p :"); scanf("%d", &p);

	/* C lculo de n!    */
	nf = fact(n);

	/* C lculo de p!    */
	pf = fact(p);

	/* C lculo de nmp!  */
	nmpf = fact(n-p);

	printf("Combina‡”es de %d %d a %d = %d", n, p, p,nf/(pf*nmpf));
}

int fact(int n)
{   int nf, i;

	nf = n;
	for (i=n-1; i>1; i--) nf = nf*i;

	return(nf);
}