15-11-24 system同步与异步

//打开关闭qq
#define _CRT_SECURE_N0_WARNINGS
#define _CRT_SECURE_NO_WARNINGS
#include<stdlib.h>
#include <windows.h>
#include <stdio.h>

void open()
{
	system("\"F:\\Program Files\\Tencent\\QQ\\Bin\\QQScLauncher.exe\"");
}

void close()
{
	system("taskkill /f /im QQ.exe");
}

void times()
{
	int num = 0;
	scanf("%d", &num);
	int i = 0;
	while (i < num)
	{
		Sleep(1000);
		i++;
	}
}

void main()
{

	open();
	times();
	close();
	system("pause");
}

#include <stdlib.h>
#include <Windows.h>

void main()
{
system("start notepad");//不等退出就可以执行，异步
Sleep(3000);
system("taskkill /f /im notepad.exe");
system("pause");
}