C语言:用三种不同的方法实现输入一个整数n,求1!+2!+...+n!的和答:方法一:for循环语句 include <stdio.h>void main(){int i,n,k=1,s=0;scanf("%d",&n);for(i=1;i<=n;i++){k*=i;s+=k;}printf("s=%d",s);}方法二:while循环语句 include <stdio.h>void main(){int i=1,n,k=1,s=0;scanf("%d",&n);while(i<=n){k*=i;s+=k;...