100的阶乘在C语言中怎么编程（要求用while和for两种方法）？

Answer 1

#include "stdio.h"

double WhileFun()
{
double sum=1, i=1;
while(i<=100)
{
sum*=i;
i++;
}
return sum;

}
double ForFun()
{
double sum=1,i=0;
for(i=0;i<100;i++)
{
sum*=(i+1);
}
return sum;
}

void main()
{
printf("%d\n",ForFun());
printf("%d\n",WhileFun());

}

Answer 2

#include <stdio.h>
main()
{int i,n;
double fac=1;//fac若为整形，则求17！就会出现数据溢出现象；另注意fac的初值
printf("Enter a positive integer:");
scanf("%d",&n);
for(i=1;i<=n,i++)
fac=fac*i;
printf("%d!=%.0f\n",n,fac);//%.0f表示不输出小数点后部分
}

Answer 3

#include <iostream.h>
void main()
{
double sum=1;
int i=100;
while( i > 1 )
{
sum*=i;
i--;
}
cout<<sum<<endl;

sum =1;
for(i=1;i<=100;i++)
{
sum*=i;
}
cout<<sum<<endl;

}