编辑代码

//E1
/*
#include <stdio.h>
int sequence (int num)
int main () 
{
    int num = 0;
    scanf("%d",&num);
    
    return 0;
}
*/

//E2
/*
#include <stdio.h>
int sum_sequence (int num)
{
    if(num == 1)
    {
        return 1;
    }
    return num + sum_sequence(num - 1);
}
int main ()
{
    int num = 0;
    scanf("%d",&num);
    printf("%d",sum_sequence(num));
    return 0;
}
*/

//E3
/*
#include <stdio.h>

int main ()
{
    return 0;
}
*/