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Update stack and queue.

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This commit is contained in:
Yudong Jin
2022-11-30 02:27:26 +08:00
parent 53cc651af2
commit 8669e06414
24 changed files with 705 additions and 186 deletions
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10
codes/java/chapter_stack_and_queue/array_queue.java
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@@ -10,10 +10,9 @@ import java.util.*;
/* 基于环形数组实现的队列 */
class ArrayQueue {
int[] nums; // 用于存储队列元素的数组
int size = 0; // 队列长度（即元素个数）
int front = 0; // 头指针，指向队首
int rear = 0; // 尾指针，指向队尾 + 1
private int[] nums; // 用于存储队列元素的数组
private int front = 0; // 头指针，指向队首
private int rear = 0; // 尾指针，指向队尾 + 1
public ArrayQueue(int capacity) {
// 初始化数组
@@ -108,12 +107,13 @@ public class array_queue {
/* 判断队列是否为空 */
boolean isEmpty = queue.isEmpty();
System.out.println("队列是否为空 = " + isEmpty);
/* 测试环形数组 */
for (int i = 0; i < 10; i++) {
queue.offer(i);
queue.poll();
System.out.println("第 " + i + " 轮入队+出队后 queue = " + Arrays.toString(queue.toArray()));
System.out.println("第 " + i + " 轮入队 + 出队后 queue = " + Arrays.toString(queue.toArray()));
}
}
}

17
codes/java/chapter_stack_and_queue/array_stack.java
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@@ -10,15 +10,15 @@ import java.util.*;
/* 基于数组实现的栈 */
class ArrayStack {
ArrayList<Integer> list;
private ArrayList<Integer> stack;
public ArrayStack() {
// 初始化列表（动态数组）
list = new ArrayList<>();
stack = new ArrayList<>();
}
/* 获取栈的长度 */
public int size() {
return list.size();
return stack.size();
}
/* 判断栈是否为空 */
@@ -28,27 +28,27 @@ class ArrayStack {
/* 入栈 */
public void push(int num) {
list.add(num);
stack.add(num);
}
/* 出栈 */
public int pop() {
return list.remove(size() - 1);
return stack.remove(size() - 1);
}
/* 访问栈顶元素 */
public int peek() {
return list.get(size() - 1);
return stack.get(size() - 1);
}
/* 访问索引 index 处元素 */
public int get(int index) {
return list.get(index);
return stack.get(index);
}
/* 将 List 转化为 Array 并返回 */
public Object[] toArray() {
return list.toArray();
return stack.toArray();
}
}
@@ -79,5 +79,6 @@ public class array_stack {
/* 判断是否为空 */
boolean isEmpty = stack.isEmpty();
System.out.println("栈是否为空 = " + isEmpty);
}
}

11
codes/java/chapter_stack_and_queue/deque.java
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@@ -10,7 +10,7 @@ import java.util.*;
public class deque {
public static void main(String[] args) {
/* 初始化队列 */
/* 初始化双向队列 */
Deque<Integer> deque = new LinkedList<>();
/* 元素入队 */
@@ -19,7 +19,7 @@ public class deque {
deque.offerLast(4);
deque.offerFirst(3);
deque.offerFirst(1);
System.out.println("队列 deque = " + deque);
System.out.println("双向队列 deque = " + deque);
/* 访问队首元素 */
int peekFirst = deque.peekFirst();
@@ -33,11 +33,12 @@ public class deque {
int pollLast = deque.pollLast();
System.out.println("队尾出队元素 pollLast = " + pollLast + "，队尾出队后 deque = " + deque);
/* 获取队列的长度 */
/* 获取双向队列的长度 */
int size = deque.size();
System.out.println("队列长度 size = " + size);
System.out.println("双向队列长度 size = " + size);
/* 判断队列是否为空 */
/* 判断双向队列是否为空 */
boolean isEmpty = deque.isEmpty();
System.out.println("双向队列是否为空 = " + isEmpty);
}
}

1
codes/java/chapter_stack_and_queue/linkedlist_queue.java
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@@ -77,5 +77,6 @@ public class linkedlist_queue {
/* 判断队列是否为空 */
boolean isEmpty = queue.isEmpty();
System.out.println("队列是否为空 = " + isEmpty);
}
}

37
codes/java/chapter_stack_and_queue/linkedlist_stack.java
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@@ -7,18 +7,20 @@
package chapter_stack_and_queue;
import java.util.*;
import include.*;
/* 基于链表实现的栈 */
class LinkedListStack {
LinkedList<Integer> list;
private ListNode stackPeek; // 将头结点作为栈顶
private int stackSize = 0; // 栈的长度
public LinkedListStack() {
// 初始化链表
list = new LinkedList<>();
stackPeek = null;
}
/* 获取栈的长度 */
public int size() {
return list.size();
return stackSize;
}
/* 判断栈是否为空 */
@@ -28,22 +30,38 @@ class LinkedListStack {
/* 入栈 */
public void push(int num) {
list.addLast(num);
ListNode node = new ListNode(num);
node.next = stackPeek;
stackPeek = node;
stackSize++;
}
/* 出栈 */
public int pop() {
return list.removeLast();
if (size() == 0)
throw new IndexOutOfBoundsException();
int num = peek();
stackPeek = stackPeek.next;
stackSize--;
return num;
}
/* 访问栈顶元素 */
public int peek() {
return list.getLast();
if (size() == 0)
throw new IndexOutOfBoundsException();
return stackPeek.val;
}
/* 将 List 转化为 Array 并返回 */
public Object[] toArray() {
return list.toArray();
public int[] toArray() {
ListNode node = stackPeek;
int[] res = new int[size()];
for (int i = res.length - 1; i >= 0; i--) {
res[i] = node.val;
node = node.next;
}
return res;
}
}
@@ -74,5 +92,6 @@ public class linkedlist_stack {
/* 判断是否为空 */
boolean isEmpty = stack.isEmpty();
System.out.println("栈是否为空 = " + isEmpty);
}
}

1
codes/java/chapter_stack_and_queue/queue.java
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@@ -35,5 +35,6 @@ public class queue {
/* 判断队列是否为空 */
boolean isEmpty = queue.isEmpty();
System.out.println("队列是否为空 = " + isEmpty);
}
}

18
codes/java/chapter_stack_and_queue/stack.java
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@@ -11,22 +11,23 @@ import java.util.*;
public class stack {
public static void main(String[] args) {
/* 初始化栈 */
Stack<Integer> stack = new Stack<>();
// 在 Java 中，推荐将 LinkedList 当作栈来使用
LinkedList<Integer> stack = new LinkedList<>();
/* 元素入栈 */
stack.push(1);
stack.push(3);
stack.push(2);
stack.push(5);
stack.push(4);
stack.addLast(1);
stack.addLast(3);
stack.addLast(2);
stack.addLast(5);
stack.addLast(4);
System.out.println("栈 stack = " + stack);
/* 访问栈顶元素 */
int peek = stack.peek();
int peek = stack.peekLast();
System.out.println("栈顶元素 peek = " + peek);
/* 元素出栈 */
int pop = stack.pop();
int pop = stack.removeLast();
System.out.println("出栈元素 pop = " + pop + "，出栈后 stack = " + stack);
/* 获取栈的长度 */
@@ -35,5 +36,6 @@ public class stack {
/* 判断是否为空 */
boolean isEmpty = stack.isEmpty();
System.out.println("栈是否为空 = " + isEmpty);
}
}