数据结构之队列的实现

java 实现

/**
 * Created by duia on 2018/5/4.
 * 链表实现队列
 */

public interface IQueue<T> {

    /**
     * 入队
     * @param data
     */
    public abstract void push(T data);


    /**
     * 出队
     * @return
     */
    public abstract T pop();
}

/**
 * Created by duia on 2018/5/4.
 */

public class QueueImp<T> implements IQueue<T> {

    /**
     * 队列头指针
     */
    private Node<T> mHead;

    /**
     * 队列尾指针
     */
    private Node<T> mTail;


    @Override
    public void push(T data) {

        //头指针为null说明是空队列
        if(null == mHead){
            mHead = mTail;
        }

        Node<T> node = new Node<>();
        node.obj = data;
        if(null != mTail){
            mTail.next = node;
        }
        mTail = node;
    }

    @Override
    public T pop() {
        if(mHead == null){
            return null;
        }
        Node<T> temp = mHead;
        T ret = mHead.obj;
        mHead = mHead.next;
        temp = null;
        return ret;
    }
}

测试

 public static void main(String[] args) {

        QueueImp<Integer> integerQueueImp = new QueueImp<>();
        integerQueueImp.push(1);
        integerQueueImp.push(2);
        integerQueueImp.push(3);

        Integer current = integerQueueImp.pop();
        while (null != current){
            System.out.println(current);
            current = integerQueueImp.pop();
        }
}

c++ 实现

#include <iostream>
using namespace std;
typedef int dataType;

typedef struct Node{

    dataType data;
    struct Node *next;
}HaHa,*pointer;

pointer head,tail;

void push23(dataType data);
dataType pop23();

int main()
{
    //using namespace std;
    //sayHello();
    //cout << "hello" << endl;
    //sayHehe();

    //int arr[8] = {1,2,3,4,5,6,7,8};

    //sum_arr(arr + 2, arr + 5);
    if (NULL == head)
    {
        head = tail;
        cout << "hahha" << endl;
    }
    push23(1);
    push23(2);
    push23(3);

    int current = pop23();
    while(-1 != current)
    {
        printf("%d\n", current);
        current = pop23();
    }
    cout << "hello world!" << endl;

    return 0;
}

void push23(dataType data)
{
    HaHa *node = new HaHa();
    node->data = data;

    if (NULL == head)
    {
        head = tail = node;
    }else{
        tail->next = node;
        tail = node;
    }
}

dataType pop23()
{
    if (head == NULL)
    {
        return -1;
    }
    Node* temp = head;
    head = head->next;
    dataType ret = temp->data;
    delete temp;
    return ret;
}