Add new Iceberg game example.

+ how to use pip to install external package
+ how to revise code

README.md

@@ -3,7 +3,7 @@
 ## 2024秋
 
 > [**UCAS本科CTF编程练习平台**](https://ucas-ctf.github.io/Coding)
-> 
+>
 > 目前仅更新了部分题目，测评系统和更多习题敬请期待！
 
 ### 第零次课————虚拟机的安装
@@ -132,5 +132,21 @@
 
 [C语言进阶——C风格字符串](https://ucas-ctf.github.io/posts/2024/2_advanced_C/string)
 
+</div>
+</details>
+
+### 第七次课 ———— Python 入门
+
+<details>
+<summary>点击展开</summary>
+<div markdown="1">
+
+#### 讲义
+
+[Basic Python Introduction](https://ucas-ctf.github.io/posts/2024/3_basic_Python/trivial-python-introduction)
+
+[Learn Some Python with Retro Computer Battle Games](https://ucas-ctf.github.io/posts/2024/3_basic_Python/learn-some-python-with-retro-computer-battle-games)
+
+
 </div>
 </details>

posts/2024/3_basic_Python/learn-some-python-with-retro-computer-battle-games.md

@@ -25,6 +25,7 @@ BASIC 语言, 而非 Python). 不过你可以将其作为课外消遣读物,
 + [Robot Missile](#robot-missile)
 + [The Vital Message](the-vital-message)
 + [Shootout](shootout)
++ [Iceberg](iceberg)
 
 ## Robot Missile
 > The year is 2582 and the people of Earth are in the midst of battle
@@ -193,4 +194,99 @@ BASIC 代码 (其实不管是什么代码都行), 然后我们需要将其变成
 我们可以考虑用这个 BASIC 来作为一个简单虚拟机的练习.
 
 ## Iceberg
-> 
+> Your hull is badly damaged and you've no weapons to speak of.
+> As you limp slowly home through treacherous iceberg-strewn waters,
+> you become aware that an enemy ship is tailing you. Strangely it can
+> detect you but not the icebergs, so your best chance is to lure it
+> into hitting one.
+>
+> Your computer will print a grid showing the position of your ship
+> (🚢), the enemy (😈) and the icebergs (🏔️). You can move one space North,
+> South, East or West each go. The enemy moves towards you by the most
+> direct route (it can move diagonally too). If you move into any of the
+> 8 positions surrounding the enemy, you will be captured, and if you hit
+> an iceberg you will sink.
+>
+> Can you escape?
+
+是时候该从这些过于朴实无华的终端文本界面升级一下了,
+我们将会演示如何下载并调用一个 TUI 的图形库: `curses`.
+
+
+
+我们最终的目标是做一个能够显示如下效果的小游戏:
+
+```text
+```
+
+### PIP, the python package manager
+这里默认大家使用的是 Windows 作为自己的编程环境, 假如是 Unix-like 的环境,
+那么大家可以只是看看这里的操作而不必真的执行下面的命令:
+
+1. 打开命令提示符或者任意包含 conda / Python 的环境
+2. 输入 `pip` 命令:
+
+```shell
+pip install windows-curses
+```
+
+这里, 我们使用 `pip install` 命令来下载一个叫作 `windows-curses` 的库.
+
+类似的, 你完全可以下载其他任何的库, 比如 `numpy`, `scipy` 等等.
+
+### 那么, 如何使用 `curses` 库呢?
+首先, 相信大家的第一个想法就是跑到万能的互联网上搜索 `curses 教程`
+关键词来找到或是 CSDN 或是 b 站视频或是别的什么的网站来找一个教程.
+
+但是, 其实还有一个非常好用的文档/教程来源: 那就是官方的文档: [curses](https://docs.python.org/3/howto/curses.html).
+让我们来看看下面的这段代码:
+
+```python
+# from https://docs.python.org/3/howto/curses.html#starting-and-ending-a-curses-application
+from curses import wrapper
+
+def main(stdscr):
+    # Clear screen
+    stdscr.clear()
+
+    # This raises ZeroDivisionError when i == 10.
+    for i in range(0, 11):
+        v = i-10
+        stdscr.addstr(i, 0, '10 divided by {} is {}'.format(v, 10/v))
+
+    stdscr.refresh()
+    stdscr.getkey()
+
+wrapper(main)
+```
+
+将这段代码保存到一个 Python 文件中: [curses-example.py](./src/computer-battle-game/curses-example.py),
+然后在终端中运行 `python curses-exaple.py`.
+
+<details>
+<summary>为什么一定要在终端中运行? </summary>
+<div markdown="1">
+
+因为大部分的 IDE 的终端是终端模拟器而非完整的终端,
+而 curses 的背后其实是 C 的 curses 库, 需要一个终端环境.
+
+</div>
+</details>
+
+### 假设大家已经差不多了解了 curses 这个库了 (大概)
+那么请参考代码: [iceberg.py](./src/computer-battle-game/iceberg.py).
+
+<details>
+<summary>代码都写完了, 那么接下来做什么? </summary>
+<div markdown="1">
+
+其实代码写完了并不意味着这个程序就没有继续升级的地方了.
+我们可以添加许多有意思的功能, 或者对代码进行重构和优化,
+以提升可读性或是性能.
+
+在这里我们将会以 Iceberg 的代码为例进行一定的优化和一般化.
+假如还有时间的话, 我们可以介绍一下该如何用 OOP 的方式,
+来重新构造这个小游戏的代码.
+
+</div>
+</details>

posts/2024/3_basic_Python/src/computer-battle-game/curses-example.py

@@ -0,0 +1,16 @@
+# from https://docs.python.org/3/howto/curses.html#starting-and-ending-a-curses-application
+from curses import window, wrapper
+
+def main(stdscr : window):
+    # Clear screen
+    stdscr.clear()
+
+    for i in range(0, 11):
+        v = i + 1
+        stdscr.addstr(i, 0, f"10 divided by {v} is {10 / v}")
+
+    stdscr.refresh()
+    stdscr.getkey()
+
+if __name__ == "__main__":
+    wrapper(main)

posts/2024/3_basic_Python/src/computer-battle-game/iceberg.py

@@ -0,0 +1,116 @@
+from time import sleep
+from random import randint
+import curses
+
+# 注: 这个代码为了展示重构, 所以特地把所有的内容都写在一起了,
+# 请不要学习这样的错误做法.
+
+stdscr = curses.initscr()
+
+# 打印欢迎信息
+stdscr.clear()
+stdscr.addstr(0, 0, "ICEBERG")
+stdscr.refresh()
+
+## 初始化代码
+
+# 这里我们用了一个小技巧来新建了一个 8x8 的空列表
+iceberg_map = [[" " for i in range(8)] for j in range(8)]
+iceberg_num = randint(4, 12)
+
+# 这里我们使用 list of list 对双重的列表元素进行取值
+for i in range(iceberg_num):
+    iceberg_map[randint(0, 7)][randint(0, 7)] = "#"
+
+# 这里我们要找一个空格子并将敌人画在上面
+enemy_x, enemy_y = randint(0, 7), randint(0, 7)
+while iceberg_map[enemy_y][enemy_x] != " ":
+    enemy_x, enemy_y = randint(0, 7), randint(0, 7)
+iceberg_map[enemy_y][enemy_x] = "Z"
+
+# 同理, 我们将自己画在上面
+# 思考: 是否这里的两段代码可以复用?
+player_x, player_y = randint(0, 7), randint(0, 7)
+while iceberg_map[player_y][player_x] != " ":
+    player_x, player_y = randint(0, 7), randint(0, 7)
+iceberg_map[player_y][player_x] = "Y"
+
+## 老板说在这里加上一个 sleep 函数, 后期让用户花钱买显卡以升级 pro 版,
+## 到时候把这个 sleep 减少一点以让用户之后买更好的卡.
+sleep(1)
+
+# event loop
+while True:
+    # 绘制地图
+    stdscr.clear()
+    for y in range(8):
+        for x in range(8):
+            stdscr.addstr(y, x, iceberg_map[y][x])
+    stdscr.addstr(8, 0, "DIRECTION (WASD to move)")
+    stdscr.refresh()
+
+    # 读取用户按键信息并进行移动
+    iceberg_map[player_y][player_x] = " "
+    while True:
+        direction = stdscr.getkey()
+        if direction == "w" and player_y != 0:
+            player_y = player_y - 1
+            break
+        elif direction == "s" and player_y != 7:
+            player_y = player_y + 1
+            break
+        elif direction == "a" and player_x != 0:
+            player_x = player_x - 1
+            break
+        elif direction == "d" and player_x != 7:
+            player_x = player_x + 1
+            break
+        elif direction == "q":
+            break
+
+    # 游戏终止
+    if direction == "q":
+        stdscr.clear()
+        stdscr.addstr(0, 0, "Game Aborted")
+        stdscr.refresh()
+        break
+
+    # 检测是否撞到冰山
+    if iceberg_map[player_y][player_x] == "#":
+        stdscr.addstr(8, 0, "YOU'VE HIT AN ICEBERG!           ")
+        stdscr.refresh()
+        break
+
+    # 检测是否被敌人抓住
+    if iceberg_map[player_y][player_x] == "Z":
+        stdscr.addstr(8, 0, "YOU'VE BEEN CAUGHT           ")
+        stdscr.refresh()
+        break
+
+    # 移动
+    iceberg_map[player_y][player_x] = "Y"
+
+    # 敌人移动
+    iceberg_map[enemy_y][enemy_x] = " "
+
+    # 这里用到了 Python 的 "三目运算符"
+    # 注: 只是类似的东西, 和 C 的还是有点区别
+    enemy_x += 1 if player_x > enemy_x else -1
+    enemy_y += 1 if player_y > enemy_y else -1
+
+    # 检测敌人是否撞到冰山
+    if iceberg_map[enemy_y][enemy_x] == "#":
+        stdscr.addstr(8, 0, "YOU'RE SAFE - HE'S HIT ONE!    ")
+        stdscr.refresh()
+        break
+
+    # 检测敌人是否抓到我们
+    if iceberg_map[enemy_y][enemy_x] == "Y":
+        stdscr.addstr(8, 0, "YOU'VE BEEN CAUGHT         ")
+        stdscr.refresh()
+        break
+
+    # 移动
+    iceberg_map[enemy_y][enemy_x] = "Z"
+
+stdscr.getkey()