可参考:https://www.runoob.com/cprogramming/c-exercise-example19.html
供参考:
#include <stdio.h>
int main()
{
int N = 1000, i, n, s;
//scanf("%d", &N);
for (n = 2; n <= N; n++)
{
for (i = 1, s = 0; i <= n / 2; i++)
{
if (n % i == 0)
{
s = s + i;
}
}
if (s == n)
{
printf("%d: its factors are 1", n);
for (i = 2; i <= n / 2; i++)
{
if (n % i == 0)
printf(" %d", i);
}
printf("\n");
}
}
return 0;
}