找出一个范围中的所有完数

#include<stdio.h>
int Com(int i);
int main()
{
int begin, end, a=0;
scanf("%d %d", &begin, &end);
for (begin; begin <= end; end--)
{
if (Com(end))
{
a = end;
break;
}
}
for (begin; begin <= end; begin++)
{
if (Com(begin) && begin != a)
{
printf("%d ", begin);
}
else if (Com(begin) && begin == a)
{
printf("%d", a);
}
}
if (a == 0) printf("NIL\n");

system("pause");
return 0;
}
int Com(int i)
{
int c=0, d=0;
if (i > 1)
{
for (int b = 1; b < i; b++)
{
if (i%b == 0)
{
d += b;
}
}
if (d == i) c = 1;
}
return c;
}