用Ｃ或C++描述循环队列每种操作在顺序循环队列或链队上的实现

以下是用C语言描述循环队列每种操作在顺序循环队列上的实现：

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

#define MAXSIZE 10

typedef struct {
    int data[MAXSIZE];
    int front, rear;
} SqQueue;

void InitQueue(SqQueue *q) {
    q->front = q->rear = 0;
}

int QueueLength(SqQueue q) {
    return (q.rear - q.front + MAXSIZE) % MAXSIZE;
}

int EnQueue(SqQueue *q, int x) {
    if ((q->rear + 1) % MAXSIZE == q->front) {
        printf("Queue is full.\n");
        return 0;
    }
    q->data[q->rear] = x;
    q->rear = (q->rear + 1) % MAXSIZE;
    return 1;
}

int DeQueue(SqQueue *q, int *x) {
    if (q->front == q->rear) {
        printf("Queue is empty.\n");
        return 0;
    }
    *x = q->data[q->front];
    q->front = (q->front + 1) % MAXSIZE;
    return 1;
}

int main() {
    SqQueue q;
    InitQueue(&q);

    EnQueue(&q, 1);
    EnQueue(&q, 2);
    EnQueue(&q, 3);

    int len = QueueLength(q);
    printf("Queue length: %d\n", len);

    int x;
    DeQueue(&q, &x);
    printf("DeQueue: %d\n", x);

    len = QueueLength(q);
    printf("Queue length: %d\n", len);

    return 0;
}

以下是用C语言描述循环队列每种操作在链队列上的实现：

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

typedef struct QNode {
    int data;
    struct QNode *next;
} QNode, *QueuePtr;

typedef struct {
    QueuePtr front, rear;
} LinkQueue;

void InitQueue(LinkQueue *q) {
    q->front = q->rear = (QueuePtr)malloc(sizeof(QNode));
    if (!q->front) {
        printf("Malloc failure.\n");
        exit(1);
    }
    q->front->next = NULL;
}

int QueueLength(LinkQueue q) {
    int len = 0;
    QueuePtr p = q.front->next;
    while (p) {
        len++;
        p = p->next;
    }
    return len;
}

int EnQueue(LinkQueue *q, int x) {
    QueuePtr p = (QueuePtr)malloc(sizeof(QNode));
    if (!p) {
        printf("Malloc failure.\n");
        exit(1);
    }
    p->data = x;
    p->next = NULL;
    q->rear->next = p;
    q->rear = p;
    return 1;
}

int DeQueue(LinkQueue *q, int *x) {
    if (q->front == q->rear) {
        printf("Queue is empty.\n");
        return 0;
    }
    QueuePtr p = q->front->next;
    *x = p->data;
    q->front->next = p->next;
    if (q->rear == p) {
        q->rear = q->front;
    }
    free(p);
    return 1;
}

int main() {
    LinkQueue q;
    InitQueue(&q);

    EnQueue(&q, 1);
    EnQueue(&q, 2);
    EnQueue(&q, 3);

    int len = QueueLength(q);
    printf("Queue length: %d\n", len);

    int x;
    DeQueue(&q, &x);
    printf("DeQueue: %d\n", x);

    len = QueueLength(q);
    printf("Queue length: %d\n", len);

    return 0;
}