W3Schools Tryit 编辑器 - W3Schools 中文教程

Python

Java

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

class Queue:
    def __init__(self):
        self.front = None
        self.rear = None
        self.length = 0
    
    def enqueue(self, element):
        new_node = Node(element)
        if self.rear is None:
            self.front = self.rear = new_node
            self.length += 1
            return
        self.rear.next = new_node
        self.rear = new_node
        self.length += 1
    
    def dequeue(self):
        if self.isEmpty():
            return "Queue is empty"
        temp = self.front
        self.front = temp.next
        self.length -= 1
        if self.front is None:
            self.rear = None
        return temp.data
    
    def peek(self):
        if self.isEmpty():
            return "Queue is empty"
        return self.front.data
    
    def isEmpty(self):
        return self.length == 0
    
    def size(self):
        return self.length

def printQueue(self):
        temp = self.front
        while temp:
            print(temp.data, end=" ")
            temp = temp.next
        print()

# Create a queue
myQueue = Queue()

myQueue.enqueue('A')
myQueue.enqueue('B')
myQueue.enqueue('C')
print("Queue: ", end="")
myQueue.printQueue()

print("Dequeue: ", myQueue.dequeue())

print("Peek: ", myQueue.peek())

print("isEmpty: ", myQueue.isEmpty())

print("Size: ", myQueue.size())

#Python

#include <stdio.h>
#include <stdlib.h>

typedef struct Node {
    char data;
    struct Node* next;
} Node;

typedef struct {
    Node* front;
    Node* rear;
    int length;
} Queue;

Queue* createQueue() {
    Queue* newQueue = (Queue*)malloc(sizeof(Queue));
    newQueue->front = NULL;
    newQueue->rear = NULL;
    newQueue->length = 0;
    return newQueue;
}

void enqueue(Queue* q, char element) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = element;
    newNode->next = NULL;
    if (q->rear == NULL) {
        q->front = q->rear = newNode;
        q->length++;
        return;
    }
    q->rear->next = newNode;
    q->rear = newNode;
    q->length++;
}

char dequeue(Queue* q) {
    if (q->length == 0) {
        printf("Queue is empty\n");
        return ' ';
    }
    Node* temp = q->front;
    q->front = temp->next;
    if (q->front == NULL) {
        q->rear = NULL;
    }
    q->length--;
    char dequeued = temp->data;
    free(temp);
    return dequeued;
}

char peek(Queue* q) {
    if (q->length == 0) {
        printf("Queue is empty\n");
        return ' ';
    }
    return q->front->data;
}

int isEmpty(Queue* q) {
    return q->length == 0;
}

int size(Queue* q) {
    return q->length;
}

void printQueue(Queue* q) {
    Node* temp = q->front;
    while (temp) {
        printf("%c ", temp->data);
        temp = temp->next;
    }
    printf("\n");
}

int main() {
    Queue* myQueue = createQueue();
    
    enqueue(myQueue, 'A');
    enqueue(myQueue, 'B');
    enqueue(myQueue, 'C');
    printf("Queue: ");
    printQueue(myQueue);
    
    printf("Dequeue: %c\n", dequeue(myQueue));
    printf("Peek: %c\n", peek(myQueue));
    printf("isEmpty: %d\n", isEmpty(myQueue));
    printf("Size: %d\n", size(myQueue));

return 0;
}

//C

public class Main {
    public static void main(String[] args) {
        Queue myQueue = new Queue();
        
        myQueue.enqueue('A');
        myQueue.enqueue('B');
        myQueue.enqueue('C');
        System.out.print("Queue: ");
        myQueue.printQueue();
        
        System.out.println("Dequeue: " + myQueue.dequeue());
        System.out.println("Peek: " + myQueue.peek());
        System.out.println("isEmpty: " + myQueue.isEmpty());
        System.out.println("Size: " + myQueue.size());
    }
}

class Node {
    char data;
    Node next;
    
    public Node(char data) {
        this.data = data;
        this.next = null;
    }
}

class Queue {
    Node front;
    Node rear;
    int length;
    
    public Queue() {
        this.front = null;
        this.rear = null;
        this.length = 0;
    }
    
    public void enqueue(char element) {
        Node newNode = new Node(element);
        if (this.rear == null) {
            this.front = this.rear = newNode;
            length++;
            return;
        }
        this.rear.next = newNode;
        this.rear = newNode;
        length++;
    }
    
    public char dequeue() {
        if (isEmpty()) {
            System.out.println("Queue is empty");
            return ' ';
        }
        Node temp = this.front;
        this.front = temp.next;
        if (this.front == null) {
            this.rear = null;
        }
        length--;
        return temp.data;
    }
    
    public char peek() {
        if (isEmpty()) {
            System.out.println("Queue is empty");
            return ' ';
        }
        return this.front.data;
    }
    
    public boolean isEmpty() {
        return length == 0;
    }
    
    public int size() {
        return length;
    }
    
    public void printQueue() {
        Node temp = this.front;
        while (temp != null) {
            System.out.print(temp.data + " ");
            temp = temp.next;
        }
        System.out.println();
    }
}

//Java