[2021 Spring] CS61A Project 3: Ants Vs. SomeBees (Phase 3)

項目說明：https://inst.eecs.berkeley.edu/~cs61a/sp21/proj/ants/
螞蟻大戰蜜蜂 靈感來源：植物大戰僵屍（Plants Vs. Zombies，PVZ）
Phase 1： https://www.cnblogs.com/ikventure/p/14986805.html
Phase 2： https://www.cnblogs.com/ikventure/p/14988467.html
Phase 3： https://www.cnblogs.com/ikventure/p/14992754.html
Phase 4： https://www.cnblogs.com/ikventure/p/14994734.html
效果展示： https://www.cnblogs.com/ikventure/p/15001093.html

目錄

• Phase 3: More Ants!
  • Problem 6 (2 pt)
  • Problem 7 (3 pt)
  • Problem 8 (3 pt)
  • Problem 9 (1 pt)

Phase 3: More Ants!

繼續添加螞蟻類型

Problem 6 (2 pt)

WallAnt類似PVZ堅果牆，高生命不攻擊。

Class	Food Cost	Initial Health
WallAnt	4	4

action：堅果牆自身不行動，action方法從Insect類繼承即可。
名稱：wall.name = 'Wall'
health：初始化時傳入，默認4
只要是需要實例化的Ant類，都要把implemented設為True。
補充一下注釋比較好看。
代碼：

# BEGIN Problem 6
# The WallAnt class
class WallAnt(Ant):
    """WallAnt does nothing each turn but it has a large health value."""

    name = 'Wall'
    food_cost = 4
    implemented = True

    def __init__(self, health=4):
        super().__init__(health)
# END Problem 6

Problem 7 (3 pt)

HungryAnt類似PVZ大嘴花，可以吞掉自身位置的隨機一只蜜蜂，但是吞掉蜜蜂后需要等待3回合的咀嚼CD，沒有蜜蜂時不行動。

Class	Food Cost	Initial Health
HungryAnt	4	1

思路：
chewing是實例屬性，每個實例獨立CD，初始化為0
名稱：'Hungry'
chew_duration為類屬性

action：
當self.chewing為0且當前位置有蜜蜂則隨機選擇一個，health置0，注意置0后要從當前位置清出。
其他情況CD不為0則減1。

代碼：

# BEGIN Problem 7
# The HungryAnt Class
class HungryAnt(Ant):
    """A HungryAnt will select a random Bee from its place and eat it whole"""

    name = 'Hungry'
    food_cost = 4
    implemented = True
    chew_duration = 3

    def __init__(self, health=1):
        super().__init__(health)
        self.chewing = 0

    def action(self, gameState):
        if self.chewing == 0 and self.place.bees[:]:
            selected_bee = bee_selector(self.place.bees)
            selected_bee.health = 0
            selected_bee.reduce_health(0)
            self.chewing = self.chew_duration
        else:
            if self.chewing != 0:
                self.chewing -= 1
# END Problem 7

Problem 8 (3 pt)

BodyguardAnt類似PVZ南瓜頭，是一種容器類螞蟻ContainerAnt，套在其他螞蟻上保護螞蟻（同一位置）。被蜜蜂攻擊時，南瓜頭掉血，內部螞蟻照常行動不掉血。南瓜頭被消滅，內部螞蟻依然留在該位置上（不再被保護）。

Class	Food Cost	Initial Health
BodyguardAnt	4	2

南瓜頭中的螞蟻存放在南瓜頭的contained_ant實例屬性中，而The container Ant南瓜頭存放在place的螞蟻實例屬性中。

ContainerAnt類：

• contain_ant方法：傳入ant設置為南瓜頭的contained_ant。
• action方法：內部存在螞蟻時，調用該螞蟻的action方法。
• can_contain方法：傳入另一只螞蟻other，在南瓜頭內沒有螞蟻（contained_ant為None），且螞蟻other不是南瓜頭（容器類螞蟻）時，返回True。

    def can_contain(self, other):
        # BEGIN Problem 8
        "*** YOUR CODE HERE ***"
        if self.contained_ant is None and not other.is_container():
            return True
        return False
        # END Problem 8

    def contain_ant(self, ant):
        # BEGIN Problem 8
        "*** YOUR CODE HERE ***"
        self.contained_ant = ant
        # END Problem 8

    def action(self, gamestate):
        # BEGIN Problem 8
        "*** YOUR CODE HERE ***"
        if self.contained_ant:
            self.contained_ant.action(gamestate)
        # END Problem 8

Ant類的add_to方法，允許一個container和一個非container螞蟻占據同一個位置，規則如下：

1. 原螞蟻可以contain被加入的螞蟻，原螞蟻調用contain_ant。
2. 被加入的螞蟻可以contain原螞蟻，被加入的螞蟻調用contain_ant，注意修改place.ant。
3. 前兩條均不滿足，觸發AssertionError。

    def add_to(self, place):
        if place.ant is None:
            place.ant = self
        else:
            # BEGIN Problem 8
            if place.ant.can_contain(self) and place.ant.contained_ant is None:
                place.ant.contain_ant(self)
            elif self.is_container() and self.can_contain(place.ant):
                self.contain_ant(place.ant)
                place.ant = self
            else:
                assert place.ant is None, 'Two ants in {0}'.format(place)
            # END Problem 8
        Insect.add_to(self, place)

BodyguardAnt類：
BodyguardAnt.__init__設置ant的初始生命值。

class BodyguardAnt(ContainerAnt):
    """BodyguardAnt provides protection to other Ants."""

    name = 'Bodyguard'
    food_cost = 4
    # OVERRIDE CLASS ATTRIBUTES HERE
    # BEGIN Problem 8
    implemented = True   # Change to True to view in the GUI

    def __init__(self, health=2):
        super().__init__(health)
    # END Problem 8

Problem 9 (1 pt)

TankAnt相當於加強版南瓜頭，可以對當前位置的所有蜜蜂造成1點傷害。

Class	Food Cost	Initial Health
TankAnt	6	2

action在BodyguardAnt的基礎上，調用Bee.reduce_health即可。
代碼：

# BEGIN Problem 9
# The TankAnt class
class TankAnt(ContainerAnt):
    """TankAnt provides protection to other Ants and make damage to Bees."""

    name = 'Tank'
    food_cost = 6
    damage = 1
    implemented = True

    def __init__(self, health=2):
        super().__init__(health)
    
    def action(self, gamestate):
        if self.contained_ant:
            self.contained_ant.action(gamestate)
        for bee in self.place.bees[:]:
            bee.reduce_health(self.damage)
# END Problem 9