求0-1000之内的“完数”，例如：6的因子是1,2,3，而6=1+2+3！

#include "stdio.h"int main(){int n,i;int s;for (n=2;n<1000;n++){s=0;for (i=1;i<n;i++){if (n%i==0){s=s+i;}}if (s==n){printf("%d its factors are ",n);for (i=1;i<n;i++){if (n%i==0){printf("%d   ",i);}}printf("\n");}}return 0;}