/* Bai tap 3_2 - Ham tinh to hop chap K cua N */

#include <stdio.h>

#include <conio.h>

unsigned long giaithua(int n)

{

unsigned long ketqua = 1;

for (i=2; i<=n; i++)

ketqua *= i;

return ketqua;

}

unsigned long to_hop_chap(int k, int n)

{

return giaithua(n) / (giaithua(k) * giaithua(n-k));

}

void main()

{

int n, k;

printf("

Nhap vao gia tri N va K : ");

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

printf("Top hop chap %d cua %d = %lu", k, n, to_hop_chap(k, n));

getch();

}