用c使用double计算s=3！+6！+9！+…+18！

#include <stdio.h>

double factorial(int n) {
double result = 1.0;
for (int i = 1; i <= n; i++) {
result *= i;
}
return result;
}

int main() {
double s = 0.0;
for (int i = 1; i <= 6; i++) {
int n = 3 * i;
double f = factorial(n);
s += f;
printf("%d! = %g\n", n, f);
}
printf("s = %g\n", s);
return 0;
}