#include <stdio.h>
#include <stdlib.h>
#define N 1000
#define P 10000
int prime(int*); // 求质数表
int factor(int *, int, int*); // 求factor
int fsum(int *, int); // sum ot proper factor
int main(void)
{
int ptable[N + 1] =
{
0
}; // 储存质数表
int fact[N + 1] =
{
0
}; // 储存因式分解结果
int count1, count2, i;
count1 = prime(ptable);
for (i = 0; i <= P; i++)
{
count2 = factor(ptable, i, fact);
if (i == fsum(fact, count2))
printf("Perfect Number: %d\n", i);
}
printf("\n");
return 0;
}
int prime(int *pNum)
{
int i, j;
int prime[N + 1];
for (i = 2; i <= N; i++)
prime[i] = 1;
for (i = 2; i *i <= N; i++)
{
if (prime[i] == 1)
{
for (j = 2 * i; j <= N; j++)
{
if (j % i == 0)
prime[j] = 0;
}
}
}
for (i = 2, j = 0; i < N; i++)
{
if (prime[i] == 1)
pNum[j++] = i;
}
return j;
}
int factor(int *table, int num, int *frecord)
{
int i, k;
for (i = 0, k = 0; table[i] *table[i] <= num;)
{
if (num % table[i] == 0)
{
frecord[k] = table[i];
k++;
num /= table[i];
}
else
i++;
}
frecord[k] = num;
return k + 1;
}
int fsum(int *farr, int c)
{
int i, r, s, q;
i = 0;
r = 1;
s = 1;
q = 1;
while (i < c)
{
do
{
r *= farr[i];
q += r;
i++;
}
while (i < c - 1 && farr[i - 1] == farr[i]);
s *= q;
r = 1;
q = 1;
}
return s / 2;
}