c语言练习25——求 1+2!+3!+4!……n!的和

#include<stdio.h>
#include<stdlib.h>
//题目:求 1+2!+3!+4!……n!的和
int main(){
int s,i,n,a,sum;
while(1){
printf("请输入参数n:");
scanf("%d",&n);
sum=0;
for(i=1;i<=n;i++){
    s=1;
    for(a=1;a<=i;a++)
    s=s*a;
    sum=sum+s;
    }
printf("1+2!+3!+……+%d!=%d\n________________________________\n",n,sum);
}
return 0;
}