程序代码：

#include <stdio.h>
#define SUM(x) ((x)*((x)+1)/2)
void main()
{
    long i = 0, j = 0, p[1000]={0};
    while (scanf("%d",&p[i++])!=EOF);
    for (; j<i-1; j++) 
    *(p+j)>0?(printf("%d\n",SUM(*(p+j)))):(printf("%d\n",-1*SUM(*(p+j)*-1)+1)),j<i-2?printf("\n"):1;
}

程序代码：

#include <stdio.h>

int main(void)
{
    int n;
    while (scanf("%d", &n) != EOF)
        printf("%d\n\n", n % 2 ? (n + 1) / 2 * n : n / 2 * (n + 1));
   

    return 0;
}

printf("%d\n\n", n % 2 ? (n + 1) / 2 * n : n / 2 * (n + 1));