练习第6小题不用fact()的做法

#include

int main() {
    int i, n;
    double jieguo,sum;
    jieguo = 1;
    sum = 0;
    scanf("%d", &n);
    for (i = 1; i <= n; i++){
        jieguo = jieguo * i;
        sum = sum + jieguo;
    }
    printf("%.3f %.3f\n", jieguo,sum);

    return 0;

}