Do homework and wash clothes in multithreaded mode (the most popular and simple multithreaded example in history, no more and no explanation)

#include <windows.h>
#include <stdio.h>
#include <time.h>

DWORD winapi Dohomework ( LPVOID p)
{
	int i, j, sum = 0;
	for (i = 0; I < 30000. i++)
	{for
		(j = 0; J < 30000; J +)
		{
			sum++;//Simulate the process of a person doing a job that takes a human (CPU) time
		}
  }
	
	printf ("Sum is%d\n", sum);

	return 0;
}

void Washclotheswithwashingmachine ()
{
	int i;
	for (i = 0; i < i++)
	{
		;//simulate the process of putting clothes into a washing machine, requiring a small amount of time (CPU) to sleep

	(5000);//simulate washing process of washing machine, do not need person (CPU) spend time
}

int main ()
{
	int t1, T2;

	T1 = Clock ();
	HANDLE hthread = CreateThread (null, 0, dohomework, NULL, 0, NULL);
	Washclotheswithwashingmachine ();
	CloseHandle (hthread);
	t2 = Clock ();

	printf ("Time is%d\n", t2-t1);

	return 0;
}

The result is (multithreading):

Sum is 900000000
Time is 4999

If it is single-threaded, it is:

#include <windows.h>
#include <stdio.h>
#include <time.h>

void Dohomework ()
{
	int I, j, sum = 0;
	for (i = 0; I < 30000. i++)
	{for
		(j = 0; J < 30000; J +)
		{
			sum++;
		}
	}
	
	printf ("Sum is%d\n", sum);
}

void Washclotheswithwashingmachine ()
{
	int i;
	for (i = 0; i < i++)
	{
		;
	}

	Sleep (5000);
}

int main ()
{
	int t1, T2;

	T1 = Clock ();
	Washclotheswithwashingmachine ();
	Dohomework ();
	t2 = Clock ();

	printf ("Time is%d\n", t2-t1);

	return 0;
}

Results (single thread):

Sum is 900000000
Time is 8327

It is obvious that multithreading saves time because people are doing their homework at the same time when the washing machine washes clothes automatically.