21 lines
290 B
C
21 lines
290 B
C
|
#include <stdio.h>
|
||
|
|
unsigned long long C(int m,int n);
|
||
|
|
|
||
|
|
int main(void){
|
||
|
|
int m,n;
|
||
|
|
scanf("%d %d",&m,&n);
|
||
|
|
printf("%llu\n",C(m,n));
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
unsigned long long C(int m,int n){
|
||
|
|
int i,c = 1,tmp;
|
||
|
|
for(i = 0; i < n; i++){
|
||
|
|
c *= m-i;
|
||
|
|
}
|
||
|
|
for(i = 0; i < n; i++){
|
||
|
|
c /= n-i;
|
||
|
|
}
|
||
|
|
return c;
|
||
|
|
}
|