1.用QT实现普通贪吃蛇功能

2.实现 键盘 控制游戏 开始（按回车），实现 键盘 控制蛇移动 方向。

3.实现 按键、键盘 控制游戏的 暂停 与 继续。

4.游戏有等级设定，不同等级速度不同

5.游戏升级提示：LEVEL UP，延时后，蛇的长度恢复为3节，游戏继续。

6.游戏失败时提示：GAME OVER，延时后，回到游戏主画面。-1. With QT realize common snake function

2. Realize the keyboard control the game start (press enter and the realization of the keyboard to control the direction of movement snake.

3. Realize buttons, the keyboard control the game and continue to suspend.

4. The game have level set, different grades at different speeds

5. Game update tip: LEVEL UP, time delay, the length of the snake recovery for 3 quarter, the game to continue.

6. The GAME failed tip: GAME OVER, time delay, back to the GAME main screen.