C语言编写程序求S=1!-2!+3!+...(-1)N! N由键盘输入 输出S的值

VC6调试通过 ---------------------------------- #include main() { int n; float s=0,t=1,k=1; scanf("%d",&n); for(int i=1;i<=n;i++) { t*=i; s+=t*k; k*=-1; } printf("1-2!+3!...+(-1)%d-1*%d!=%f\n",n,n,s); }