用C语言求s=1-1/2!+1/3!-1/4!+……+1/n!其中n的值由键盘输入（急！！）

#include double factorial(int n) { double f = 1 ; for (int t=1 ; t<= n ; t++) { f = f*t ; } return f; } void main() { int n, k=1; double s = 0 ; printf("Input n\nn=") ; scanf("%d", &n) ; for (int t=1; t<=n; t++) { s = s + ((