链式队列

链式队列和链表很相似。

不过对链式队列中数据的添加是通过两个指针进行top和rear（添加和输出都是one by one）

对于链式队列有两种基本方式，一种是带有头结点，一种是没有头结点。没有头结点的方式，需要自己去获取第一次添加元素的队头。

推荐有头结点的方式，方便理解。

含有头结点方式：

#include <iostream>
#include <vector>

using namespace std;

struct Queue {
    int ele;
    Queue *next;
};

Queue *InitQueue() {
    Queue *q = new Queue;
    q->ele = NULL;
    q->next = NULL;

    return q;
}

Queue *enQueue(Queue *rear, int ele) {
    Queue *list = new Queue;
    list->ele = ele;
    list->next = NULL;
    rear->next = list;
    rear = rear->next;

    return rear;
}

Queue* deQueue(Queue *top, Queue *rear) {
    if (top->next == NULL) {
        cout << "队列为空!" << endl;
        return top;
    }

    top = top->next;
    cout << top->ele << endl;

    return top;
}

int main()
{
    Queue *top, *rear;
    top = rear = InitQueue();
    rear = enQueue(rear, 5);
    rear = enQueue(rear, 10);
    top = deQueue(top, rear);
    top = deQueue(top, rear);
    top = deQueue(top, rear);

    system("PAUSE");
    return 0;
}

 

不含有头结点的方式;

#include <iostream>
#include <vector>

using namespace std;

struct Queue {
    int ele;
    Queue *next;
};

Queue *InitQueue() {
    Queue *q = new Queue;
    q->ele = NULL;
    q->next = NULL;

    return q;
}

Queue *enQueue(Queue *rear, int ele) {
    if (rear == NULL) {
        rear = new Queue;
        rear->ele = ele;
        rear->next = NULL;
    }
    else {
        Queue *list = new Queue;
        list->ele = ele;
        list->next = NULL;
        rear->next = list;
        rear = rear->next;
    }

    return rear;
}

Queue* deQueue(Queue *top, Queue *rear) {
    if (top == NULL) {
        cout << "队列为空!" << endl;
        return top;
    }

    cout << top->ele << endl;
    top = top->next;

    return top;
}

int main()
{
    Queue *top, *rear;
    top = rear = NULL;
    top = rear = enQueue(rear, 5);
    rear = enQueue(rear, 10);
    top = deQueue(top, rear);
    top = deQueue(top, rear);
    top = deQueue(top, rear);

    system("PAUSE");
    return 0;
}