例如:求組合數C(A,B) = A!/( (A-B)! * B! )
int jie_cheng( int ) ;
void main( )
{
int a = 0,b = 0 , c = 0 ;
scanf("%d %d",&a,&b);
c = jie_cheng(a) / (jie_cheng(a-b)*jiecheng(b)) ;
printf("Zu he shu C is: %d\n", c);
}
int jie_cheng(int num)
{
if( num == 1)
return 1 ;
else
return num*jie_cheng(num-1) ;
}