刚刚开始学习C++，第一个小代码，猜数字游戏。它可以让用户猜电脑随机产生的数字，也可以让电脑在7次猜想中猜中用户想出来的数字。-Start to learn C++, and this is the first small program, guess number game. It can ask the user to guess the number that computer derived, and also can let the computer guess the user s