C语言解答

#include <stdio.h>

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

int main() {
    double sum = 0.0;
    for (int i = 1; i <= 30; i ++) {
        sum += factorial(i);
    }
    printf("%.2e\n", sum);
    return 0;
}