小编use*_*747的帖子

Prim和Kruskal的算法用于查找连接和无向图的最小生成树.为什么它们不能用于指向的图形？

我正在做一个反射游戏.这是输出 -

__________________________________________________________________________
Reflex game initiated. Press ENTER to begin the game, and then press ENTER 
after the asterisks are printed to measure your reflexes!.


*************************

Your result: 0.285606 seconds.
logout

[Process completed]
__________________________________________________________________________

但是有一个小问题 - 按下Enter键开始游戏之后和星星打印之前有0-10秒(基于随机变量).在此期间,如果玩家按下ENTER,则将其记录为反射时间.所以我需要一种方法来阻止我的代码在打印星星之前读取他们的ENTER按钮.代码 -

#!/usr/bin/perl

use Time::HiRes qw(sleep);
use Time::HiRes qw(gettimeofday);

#random delay variable
$random_number = rand();

print "Reflex game initiated. Press ENTER to begin the game, and then press ENTER after         the asterisks are printed to measure your reflexes!.\n";

#begin button
$begin = <>;

#waits …

int main()
{
   int var = 1;
   var += ++var;
   cout<<var;
   return 0;
}

在Java中,这将按预期输出3,但在C++(上面)中输出4.为什么？