链队列的基本操作实现

1. 链队列含头结点模型示意图如下：

2. 链队列结构定义如下：

// 结点类型
struct QueueNode {
	int data;
	QueueNode* next;
};

// 链队列结构
struct LinkQueue{
	QueueNode* front;
	QueueNode* rear;
};

3. 链队列的基本操作函数如下：

• LinkQueue* createLinkQueue(); // 创建队列头结点
• Insert(LinkQueue* head, int item); // 插入
• Delete(LinkQueue* head); // 出队，并返回数据

4. 具体代码实现如下：

#include <iostream>

using namespace std;

// 结点类型
struct QueueNode {
	int data;
	QueueNode* next;
};

// 链队列结构
struct LinkQueue{
	QueueNode* front;
	QueueNode* rear;
};

// 创建队列头结点
LinkQueue* createLinkQueue() {
	LinkQueue* head = (LinkQueue*)malloc(sizeof(LinkQueue));
	head->front = (QueueNode*)malloc(sizeof(QueueNode));
	head->front->data = 0;
	head->front->next = NULL;
	head->rear = head->front;
	return head;
}

// 插入
void Insert(LinkQueue* head, int item) {
	if (head == NULL) {
		head = createLinkQueue();
	}
	QueueNode* qnode = (QueueNode*)malloc(sizeof(QueueNode));
	qnode->data = item;
	qnode->next = NULL;
	head->rear->next = qnode;
	head->rear = qnode;
}

// 删除
int Delete(LinkQueue* head) {
	if (head == NULL || head->front == head->rear) {
		cout << "The linkqueue is empty." << endl;
		return 0;
	}
	QueueNode* temp = head->front->next;
	int val = temp->data;
	head->front->next = temp->next;
	if (temp == head->rear) {
		head->rear = head->front;
	}
	free(temp);
	return val;
}

int main() {
	LinkQueue* head = NULL;
	head = createLinkQueue();
	Insert(head, 1);
	Insert(head, 2);
	Insert(head, 3);
	Insert(head, 4);
	cout << Delete(head) << endl;
	cout << Delete(head) << endl;
	cout << Delete(head) << endl;
	cout << Delete(head) << endl;
	cout << Delete(head) << endl;
	system("pause");
	return 0;
}

5. 运行结果截图如下：