//enum with colors
public enum Color {
RED, YELLOW, BLUE;
}
//class for the standard Lego Brick. You can connect or disconnect the Brick, it has color
public class LegoBrick {
Color color;
boolean isConnected;
public void connect() {
System.out.println("This brick is connected");
this.isConnected = true;
}
public void disconnect() {
System.out.println("Disconnected");
isConnected = false;
}
public LegoBrick(Color color, boolean isConnected) {
this.color = color;
this.isConnected = isConnected;
}
public Color getColor() {
return color;
}
public boolean isConnected() {
return isConnected;
}
@Override
public String toString() {
return "LegoBrick{" +
"color=" + color +
", isConnected=" + isConnected +
'}';
}
}
import java.util.ArrayDeque;
public class LegoTower {
ArrayDeque<LegoBrick> myTower;
int quantityOfReds;
int quantityOfYellows;
public void addBrickToTower(LegoBrick newLegoBrick) {
if (newLegoBrick.getColor() == Color.YELLOW) {
this.myTower.offerLast(newLegoBrick);
quantityOfYellows++;
}
//we can use addFirst(e)/push(e) instead of offerFirst here
if (newLegoBrick.getColor() == Color.RED) {
myTower.offerFirst(newLegoBrick);
quantityOfReds++;
}
}
public void removeBrickFromTower (LegoBrick legoBrick) {
if (legoBrick.getColor() == Color.YELLOW) {
this.myTower.removeLast();
quantityOfYellows--;
}
if (legoBrick.getColor() == Color.RED) {
myTower.removeFirst();
quantityOfReds--;
}
legoBrick.isConnected = false;
}
public LegoTower(int quantityOfReds, int quantityOfYellows) {
myTower = new ArrayDeque<>();
this.quantityOfReds = quantityOfReds;
this.quantityOfYellows = quantityOfYellows;
for (int i = 0; i < quantityOfReds; i++) {
LegoBrick redLegoBrick = new LegoBrick(Color.RED, false);
myTower.addFirst(redLegoBrick);
redLegoBrick.isConnected = true;
}
for (int i = 0; i < quantityOfYellows; i++) {
LegoBrick yellowLegoBrick = new LegoBrick(Color.YELLOW, false);
myTower.addLast(yellowLegoBrick);
yellowLegoBrick.isConnected = true;
}
}
public void setMyTower(ArrayDeque<legobrick> myTower) {
this.myTower = myTower;
}
public void setQuantityOfReds(int quantityOfReds) {
this.quantityOfReds = quantityOfReds;
}
public void setQuantityOfYellows(int quantityOfYellows) {
this.quantityOfYellows = quantityOfYellows;
}
@Override
public String toString() {
return "LegoTower{" +
"myTower=" + myTower +
", quantityOfReds=" + quantityOfReds +
", quantityOfYellows=" + quantityOfYellows +
'}';
}
public void drawTower() {
for (LegoBrick i : myTower) {
System.out.println(i.color);
}
}
}
public class Main {
public static void main(String[] args) {
LegoBrick legoBrick1 = new LegoBrick(Color.YELLOW, false);
legoBrick1.connect();
System.out.println(legoBrick1.toString());
legoBrick1.disconnect();
System.out.println(legoBrick1.toString());
LegoBrick legoBrick2 = new LegoBrick(Color.YELLOW, false);
LegoBrick legoBrick3 = new LegoBrick(Color.RED, false);
LegoBrick legoBrick4 = new LegoBrick(Color.RED, false);
LegoBrick legoBrick5 = new LegoBrick(Color.YELLOW, false);
LegoTower legoTower = new LegoTower(2, 5);
System.out.println("my Initiated Lego Tower: ");
legoTower.drawTower();
legoTower.addBrickToTower(legoBrick1);
legoTower.addBrickToTower(legoBrick2);
legoTower.addBrickToTower(legoBrick3);
legoTower.addBrickToTower(legoBrick4);
legoTower.addBrickToTower(legoBrick5);
System.out.println("My LegoTower after adding some elements: ");
legoTower.drawTower();
legoTower.removeBrickFromTower(legoBrick1);
legoTower.removeBrickFromTower(legoBrick3);
System.out.println("We removed one red and one yellow brick:");
legoTower.drawTower();
}
}
運行這個程序的結果：
my Initiated LegoTower:
RED
RED
YELLOW
YELLOW
YELLOW
YELLOW
YELLOW
My LegoTower after adding some elements:
RED
RED
RED
RED
YELLOW
YELLOW
YELLOW
YELLOW
YELLOW
YELLOW
YELLOW
YELLOW
We removed one red and one yellow brick:
RED
RED
RED
YELLOW
YELLOW
YELLOW
YELLOW
YELLOW
YELLOW
YELLOW
Process finished with exit code 0
public class MyLinkedTest {
public static void main(String[] args) {
String h1 = "my";
String h2 = "favorite";
String h3 = "book";
// LinkedList implementation in Java
LinkedList<string> linkedList = new LinkedList();
linkedList.add(h1);
linkedList.add(h2);
linkedList.add(h3);
System.out.println("my list after adding 3 elements:");
System.out.println(linkedList);
System.out.println("element #2 of my list:");
System.out.println(linkedList.get(2));
linkedList.remove(1);
System.out.println("my list after removing #1:");
System.out.println(linkedList);
linkedList.add(1,"first");
System.out.println("my list after adding an element in the middle");
System.out.println(linkedList);
}
運行這個程序的結果：
my list after adding 3 elements:
[my, favorite, book]
element #2 of my list:
book
my list after removing #1:
[my, book]
my list after adding an element in the middle
[my, first, book]
還有一個重要的數據結構稱為 Stack，這是一個以完全相反的原則處理元素的列表，LIFO——後進先出。它類似於一堆盤子，只能在頂部添加或移除。 
“Deque”這個名字的意思是“雙端隊列”。“Deque”的發音就像一副紙牌，你知道嗎？它有點類似於一副真正的紙牌：你可以從這樣一副紙牌的底部或頂部拿一張牌。想在某些線性結構的兩側添加或刪除元素？使用雙端隊列。Java 8 或幾乎任何其他版本都支持它。想像一下典型的樂高積木和由積木製成的單柱“塔”。您可以在塔的頂部或底部添加一塊新磚。您也可以從兩側移除一塊磚。這裡有一個示例：我們將所有黃色磚塊添加到頂部，將所有紅色磚塊添加到底部。我們將很快用 Java 代碼演示這個例子。 
因此，您可以從 Java Deque 的兩端入隊和出隊，這意味著您可以將 Deque 用作隊列和堆棧。閱讀 Java 中的堆棧：Java Stack 101：深入研究堆棧類 閱讀 Java 中的隊列：Java 隊列接口及其實現
LinkedList 類在內部使用雙鍊錶來模擬隊列或雙端隊列。ArrayDeque 類將元素內部存儲在數組中。如果元素的數量超過數組的體積，則分配一個新數組，並將所有元素移過去。這意味著 ArrayDeque 根據需要增長。
LinkedList 主要被稱為 List 實現，但該類也實現了 Deque，它允許我們創建一個由包括 null 在內的任何對象組成的雙向隊列。LinkedList 是元素的集合。我們可以在類的代碼源中看到，這次注意字段：這裡我們添加一個例子，但是如果你想了解更多關於LinkedList的知識，歡迎閱讀這篇CodeGym文章。
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