队列的链表实现（c++）

实现功能（FIFO）：

1.入队push()

2.出队pop()

3.获取队头front()

4.查询队列的所有元素select()

以下C++代码采用尾插法推入与头删法推出，使得符合先进先出（FIFO）规则：

#include<iostream>

using namespace std;

class MyQueue {
	private:
		struct ListNode {
			int data;
			ListNode* next;
		};
		ListNode* head;
		
	public:
		MyQueue() {
			head = nullptr;
		}
		~MyQueue() {//采用头删法析构
			if (!head) return;
			ListNode* now = head;
			ListNode* next = nullptr;
			while (now->next) {
				next = now->next;
				delete now;
				now = next;
			}
			delete now;
			now = nullptr;
		}
		ListNode* CreateNode(int value) {
			ListNode* newNode = new ListNode;
			newNode->data = value;
			newNode->next = nullptr;

			return newNode;
		}
		//推入数据（尾插）
		void push(int value) {
			ListNode* newNode = CreateNode(value);
			if (!head) {
				head = newNode;
			} else {
				ListNode* temp = head;
				while (temp->next) {
					temp = temp->next;
				}
				temp->next = newNode;
			}
		}
		//推出数据（头删）
		void pop() {
			if (!head) {
				cout << "此队列为空，不可再删！！" << endl;
				return;
			}
			ListNode* now = head;
			ListNode* next = nullptr;
			if (now->next) {
				next = now->next;
				delete now;
				now = next;
				head = next;
			} else {
				delete now;
				now = nullptr;
			}
		}
		//查询队头
		void front() {
			if (!head) {
				cout << "队列为空！！没有队头！！" << endl;
				return;
			}
			cout << "front: " << head->data << endl;
		}
		//查询全部数据
		void select() {
			if (!head) {
				cout << "队列为空！！" << endl;
				return;
			}
			ListNode* temp = head;
			while (temp) {
				cout << temp->data << " ";
				temp = temp->next;
			}
			cout << endl;
		}
};

int main() {
	MyQueue myQueue;
	for (int i = 0; i <= 8; i++) {
		myQueue.push(i);
	}
	for (int i = 0; i <= 1; i++) {
		myQueue.pop();
	}
	myQueue.front();
	myQueue.select();
	return 0;
}

运行效果：