#C recursive factorial and

This problem required to achieve a non-negative integer factorial simple function calculations, and using the function evaluation 1! +2! +3! + ... + n! Value.

Function interface definition:

double fact( int n );
double factsum( int n );

Function factshould return nthe factorial, it is recommended to achieve recursive. Function factsumshould return 1! + 2! + ... + n! Values. Title ensure that the input and output in double precision.

Referee test program Example:

#include <stdio.h>

double fact( int n );
double factsum( int n );

int main()
{
    int n;

    scanf("%d",&n);
    printf("fact(%d) = %.0f\n", n, fact(n));
    printf("sum = %.0f\n", factsum(n));
		
    return 0;
}

/* 你的代码将被嵌在这里 */

Sample Input 1:

10

Output Sample 1:

fact(10) = 3628800
sum = 4037913

Sample Input 2:

0

Output Sample 2:

fact(0) = 1
sum = 0

 1 #include <stdio.h>
 2 double fact(int n);
 3 double factsum(int n);
 4 
 5 int main() {
 6     int n;
 7 
 8     scanf("%d", &n);
 9     printf("fact(%d) = %.0f\n", n, fact(n));
10     printf("sum = %.0f\n", factsum(n));
11 
12     return 0;
13 }
14 double fact(int n) {
15     double res, sum;
16     if (n == 1 || n == 0) {
17         res = 1;
18     } else {
19         res = n * fact(n - 1);
20     }
21     return res;
22 }
23 double factsum(int n) {
24     double sum = 0;
25     if (n == 1)
26         sum = 1;
27     else if (n == 0)
28         sum = 2;
29     else {
30         sum = fact(n) + factsum(n - 1);
31     }
32 
33     return sum;
34 }