c++代码实现链队列的基本操作

链队列的基本操作包括：初始化、入队、出队、获取队头元素、获取队列长度、清空队列、销毁队列。

下面是用 C 语言实现链队列的基本操作的代码：

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

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

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

// 初始化队列
void initQueue(Queue *queue) {
    queue->front = queue->rear = NULL;
    queue->length = 0;
}

// 入队
void enqueue(Queue *queue, int data) {
    Node *node = (Node *) malloc(sizeof(Node));
    node->data = data;
    node->next = NULL;
    if (queue->rear == NULL) {
        queue->front = queue->rear = node;
    } else {
        queue->rear->next = node;
        queue->rear = node;
    }
    queue->length++;
}

// 出队
void dequeue(Queue *queue) {
    if (queue->front == NULL) {
        printf("Queue is empty.\n");
        return;
    }
    Node *node = queue->front;
    queue->front = node->next;
    if (queue->front == NULL) {
        queue->rear = NULL;
    }
    free(node);
    queue->length--;
}

// 获取队头元素
int front(Queue *queue) {
    if (queue->front == NULL) {
        printf("Queue is empty.\n");
        return -1;
    }
    return queue->front->data;
}

// 获取队列长度
int getLength(Queue *queue) {
    return queue->length;
}

// 清空队列
void clearQueue(Queue *queue) {
    while (queue->front != NULL) {
        dequeue(queue);
    }
}

// 销毁队列
void destroyQueue(Queue *queue) {
    clearQueue(queue);
    free(queue);
}

int main() {
    Queue *queue = (Queue *) malloc(sizeof(Queue));
    initQueue(queue);
    enqueue(queue, 1);
    enqueue(queue, 2);
    enqueue(queue, 3);
    printf("Queue length: %d\n", getLength(queue));
    printf("Queue front: %d\n", front(queue));
    dequeue(queue);
    printf("Queue length: %d\n", getLength(queue));
    printf("Queue front: %d\n", front(queue));
    clearQueue(queue);
    printf("Queue length: %d\n", getLength(queue));
    destroyQueue(queue);

    return 0;
}