用C语言编程:编写一个函数,求n!

Answer 1

#include<stdio.h>
double hanshu(int A);
int main()
{
int inputN;
scanf("%d",&inputN);
double re=0.0;
re = hanshu(inputN);
printf("(%d)!=%f",inputN,re);
return 0;

}
double hanshu(int A)
{
double re=1.0;;
int i;
for(i = 1;i<=A;i++)
{
re *=i;
}
return re;
}

Answer 2

main()
{ int i,n;
long sum=1;
scanf("%d",&n);
for(i=1,i<=n,i++)
sum*=i;
printf("%ld",sum);

Answer 3

#include <stdio.h>
main()
{
int i,n,s=1;
scanf("%d",&n);
for(i=1;i<=n;i++)
{s*=i;
}
printf("%d!=%d\n",n,s);
}