PTA——组合数

 1 #include<stdio.h>
 2 double fact(int n);
 3 
 4 int main() {
 5     int m,n;
 6     int c;
 7     scanf("%d%d",&m,&n);
 8     c=(int)(fact(n)/(fact(m)*fact(n-m)));
 9     printf("result = %d",c);
10 }
11 
12 double fact(int n) {
13     double p=1.0;
14     while(n) {
15         p *= n;
16         n--;
17     }
18     return p;
19 }