#include<conio.h>

#include<stdio.h>

#include<math.h>

#include<process.h>

void nhapdulieu(int &n,int &k);

long giaithua(long n);

long sotohop(int n,int k);

int ucln(int m,int n);

void nhapps(int &tu,int &mau);

void gianuocps(int &tu,int &mau);

void inps(int tu,int mau);

void main()

{

int n,a,b;

printf("

moi ban chon chuc nang chuong trinh");

printf("

1-tinh so to hop");

printf("

2-gian uoc phan so");

printf("

3-nhan hai so");

printf("

nhap so chuc nang ban chon");

printf("

5-thoat");

if(n==5)

{

exit(0);

}

if(n==1)

{

int n,k;

long c;

nhapdulieu(n,k);

c=sotohop(n,k);

printf("so to hop la %1d",c);

}

if(n==2)

{

int t,m;

nhapps(t,m);

printf("

nhap so toi gian la");

inps(t,m);

}

getch();

}

void nhapdulieu(int &n,int &k)

{

do

{

printf("nhap n vs k");

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

}

while(k>=n);

}

long giaithua(long n)

{

long i,gt;

gt=1;

for(i=1;i<=n;i++)

{

gt=gt*i;

}

return gt;

}

long sotohop(int n,int k)

{

long ngt,kgt,nkgt,c;

ngt=giaithua(n);

kgt=giaithua(k);

nkgt=giaithua(n-k);

c=ngt/(kgt*nkgt);

return c;

}

void nhapps(int &tu,int &mau)

{

do

{

printf("nhap tu va mau");

scanf("%d%d",&tu,&mau);

if(mau==0)

printf("nhap lai");

}

while(mau==0);

}

void inps(int tu,int mau)

{

if(tu==0)

printf("0");

else

if(mau==1)

printf("%d",tu);

else

printf("%d%d",tu,mau);

}

int ucln(int m,int n)

{

while(m!=n)

{

if(m>n)

m=m-n;

else

n=n-m;

}

return m;

}

void gianuocps(int &tu,int &mau)

{

int uc=ucln(tu,mau);

tu=tu/uc;

mau=mau/uc;

}