// Perfect.cpp : Defines the entry point for the console application.
#include "stdafx.h"
#include "Windows.h"
#include "LIMITS.h"
static HANDLE Thread_semaphore;
int _tmain(int argc, _TCHAR* argv[])
{
	HANDLE hThread1;
	DWORD dwThread1ID = 0;
	HANDLE hThread2;
	DWORD dwThread2ID = 0;
	HANDLE hThread3;
	DWORD dwThread3ID = 0;
	HANDLE hThread4;
	DWORD dwThread4ID = 0;
	INT nParameter = 1;
	DWORD WINAPI PerfectThread (LPVOID lpArg);
	DWORD time_count;
	unsigned long i, j, sum;
	printf("\n");
	time_count = GetTickCount();
	for (j=2; j<=100000; j++)
	{
		sum = 0;
		for (i=1; i<j; i++)
		{
			if ((j % i) == 0) sum = sum + i;
		}
	if (sum == j) printf("%d is a perfect number\n", j);
	}
	time_count = GetTickCount() - time_count;
	printf("\n\n %d milliseconds elapsed time\n\n\r", time_count);
	Sleep(4000);
	// do it with threads
	Thread_semaphore = CreateSemaphore(NULL, 0, 4, TEXT("Thread_Done"));
	time_count = GetTickCount();
	hThread1 = CreateThread( NULL, 0, PerfectThread, (LPVOID)nParameter, 0, &dwThread1ID);
	nParameter++;
	hThread2 = CreateThread( NULL, 0, PerfectThread, (LPVOID)nParameter, 0, &dwThread2ID);
	nParameter++;
	hThread3 = CreateThread( NULL, 0, PerfectThread, (LPVOID)nParameter, 0, &dwThread3ID);
	nParameter++;
	hThread4 = CreateThread( NULL, 0, PerfectThread, (LPVOID)nParameter, 0, &dwThread4ID);
	WaitForSingleObject(Thread_semaphore, INFINITE);
	WaitForSingleObject(Thread_semaphore, INFINITE);
	WaitForSingleObject(Thread_semaphore, INFINITE);
	WaitForSingleObject(Thread_semaphore, INFINITE);
	time_count = GetTickCount() - time_count;
	printf("\n\n %d milliseconds elapsed time\n\r", time_count);
	Sleep(4000);
	CloseHandle(hThread1);
	CloseHandle(hThread2);
	CloseHandle(hThread3);
	CloseHandle(hThread4);
	return 0;
}
DWORD WINAPI PerfectThread (LPVOID lpArg) {
INT threadnumber = (INT) lpArg;
	unsigned long i, j, sum;
	for (j=1 + threadnumber; j<=100000; j=j+4)
	{
		sum = 0;
		for (i=1; i<j; i++)
		{
			if ((j % i) == 0) sum = sum + i;
		}
		if (sum == j) printf("Thread %d: %d is a perfect number\n\r", threadnumber, j);
	}
	ReleaseSemaphore(Thread_semaphore, 1, NULL);
	return 0;
}