Question

c语言编程：求s=1！+2！+3！的和的编写程序

用while或者do while ，for语句分别编写

Answer 1

#include<stdio.h>
main()
{
int a,s=0,i,j;
for(i=1;i<=3;i++)
{
a=1;
for(j=1;j<=i;j++)
a*=j;
s+=a;
}
printf("1!+2!+3!=%d\n",s);
}

#include<stdio.h>
main()
{
int a,i=1,j,s=0;
while(i<=3)
{
a=j=1;
while(j<=i)
{
a*=j;
j++;
}
s+=a;
i++;
}
printf("1!+2!+3!=%d\n",s);
}

Answer 2

//while
#include<iostream>
using namespace std;
main ()
{int s=0,i=1,i1,k;
while (i<=3)
{k=1;i1=i++;
while (i1) k*=i1--;
s+=k;}
cout<<s;}

//for:
#include<iostream>
using namespace std;
main ()
{int s=0,i=1,i1,k;
for (int i=1;i<=3;i++)
{k=1;
for (int j=1;j<=i;j++) k*=j;
s+=k;}
cout<<s;}

Answer 3

#include<stdio.h>
int fact(int n)
{
int a,s=1;
for(a=n;a>=1;a--)
s=s*a;
return s;
}
void main()
{
int sum;
sum=fact(1)+fact(2)+fact(3);
printf("sum is %d",sum);
}

Answer 4

#include"stdio.h"
#define N 3
main()
{
int i,temp=1;
long int sum=0;
for(i=1;i<N;i++)
{
temp*=i;
sum+=temp;
}
printf("%ld",sum);
}

Answer 5

long sum;
fro(int i=1;i<=3;i++)
{
for(int j =1;j<=i;j++)
{
sum = sum+j*i;
}
}

Answer 6

#include<stdio.h>
int main()
{
int n=1,i,s=0;
for(i=1;i<=3;i++)
{
n=i*n;
s=s+n;
}
printf("%d",s);
}