编写函数计算组合数：c(n,k)=n!/(k!(n-k)!)

Question

编写函数计算组合数：c(n,k)=n!/(k!(n-k)!)

Answer 1

#include
int a(int b)
{
int i,n;
int b=1;
for(i=1;i<=b;i++)
n=n*i;
return n;
}
int c(int n,int k)
{
int d;
d=int a(n)/(int a(k)*int(n-k));
return d;
}
main()
{
int e,n,k;
scanf("%d %d",n,k);
e=int c(int n,int k);
printf("%d",e);
}