Question

写出函数moveNthFront的定义，该函数将参数作为正整数n。该函数将队列的第n个元素移动到前面。其余元素的顺序保持不变。例如，假设：

queue = {5,11,34,67,43,55}和n = 3.

调用函数moveNthFront之后：

queue = {34,5,11,67,43,55}。

将此函数添加到类queueType中。另外，编写一个程序来测试你的方法。

这是我的标题

#ifndef queueType_H
#define queueType_H
#include<iostream>

class queueType
{
private:
    class Queue
    {
        friend class queueType;
        int value;
        Queue *next;
        Queue(int value1, Queue *next1 = NULL)
        {
            value = value1;
            next = next1;
        }
    };
    // These track the front and rear of the queue
    Queue *front;
    Queue *rear;
    Queue *head;


public:
   void moveNthFront(int);

这是标题的cpp。

#include"queueType.h"
#include<iostream>
using namespace std;

queueType::queueType() {
front = NULL;
rear = NULL;
}

queueType::~queueType() {
clear();
}

void queueType::enqueue(int num)
{
    if (isEmpty())
    {
        front = new Queue(num);
        rear = front;
    }
    else
    {
        rear->next = new Queue(num);
        rear = rear->next;
    }
}
void queueType::dequeue(int &num)
{
    Queue *temp;
    if (isEmpty())
    {
        cout << "The queue is empty.\n";
        exit(1);
    }
    else
    {
        num = front->value;
        temp = front;
        front = front->next;
        delete temp;
    }
}

bool queueType::isEmpty() const
{
    if (front == NULL)

        return true;
    else
        return false;
}

int queueType::search(int x)
{
    if (front == NULL)
        return -1;
    else
    {
        int count = 0;
        Queue *aptr = front;
        while (aptr != NULL)
        {
        if (aptr->value == x)
            return count;
            aptr = aptr->next;
            count++;
        }
        return -1;
    }
}

void queueType::clear()
{
    int value;   // Dummy variable for dequeue

    while (!isEmpty())
        dequeue(value);
}
void queueType::remove(int pos)
{
    if (front == NULL)
        return;
    else if (pos == 0)
        front = front->next;
    else
    {
        int count = 0;
        Queue *now = front, *past;
        while (now != NULL && count != pos)
        {
            past = now;
            now = now->next;
            count++;
        }
    if (now)
        {
            past->next = now->next;
            delete now;
        }
    }
}
void queueType::insert(int x, int pos )
{
    Queue *now, *past;
    if (front == NULL)
        front = new Queue(x);
    else if (now != NULL && pos == 0)
    {
    now = front;
    ;
        for (int i = 0; i < 5; i++)
        {
            past = now;
            now = now->next;

        }
        past->next = new Queue(x, now);
    }
    else
    {
        now = front;
        int count = 0;
        while (now != NULL && count != pos)
        {
            past = now;
            now = now->next;
            count++;
        }
        past->next = new Queue(x, now);
    }
}

这是我的主要

#include"queueType.h"
#include<iostream>
using namespace std;

int main() {

queueType intqueue;

int input, temp, x = 0;

for (int i = 0; i < 5; i++) {
    intqueue.enqueue(i*i);
}
cout << "The values in the queue were:\n";
while (!intqueue.isEmpty())
{
    int value;
    intqueue.dequeue(value);
    cout << value << "  ";
}

for (int i = 0; i < 5; i++) {
    intqueue.enqueue(i*i);
}
cout << "\nEnter the value to find:" << endl;
cin >> input;
intqueue.search(input);
temp = intqueue.search(input);
intqueue.remove(temp);
intqueue.insert(input, 0);

cout << "\nThe values after change was made:\n";
while (!intqueue.isEmpty())
{
    int value;
    intqueue.dequeue(value);
    cout << value << "  ";
}
return 0;

}

Answer 1

在插入方法中 else if (now != NULL && pos == 0) { 这部分永远不会运行，因为现在它是null，因为它从未被初始化。然后控制转到其他部分其中如果pos = 0 *过去从未初始化。现在首先初始化*。否则你可以删除其他部分，只是在while循环之外初始化*过去，即

else
{
    now = front;
    int count = 0;//here initialize past once past=now;
    while (now != NULL && count != pos)
    {
        past = now;
        now = now->next;
        count++;
    }
    past->next = new Queue(x, now);
}

Answer 2

我编辑了它。它适用于除0 pos之外的所有位置。我需要元素转到队列的前面。

<div class="icon"></div>

.icon:after {
  content: "";
  display: inline-block;
  background-color: gold;
  background-image: url(http://orig00.deviantart.net/1110/f/2014/143/9/b/mega_man_hd_sprites__transparent_background__by_lunodevan-d7jgruq.png);
  background-position: -129px -40px;
  height: 100px;
  width: 100px;

}

.icon {
  margin: auto;
  margin-top: 100px;
  position: relative;
  width: 100px;
}

.icon:before {
  content: "";
  display: inline-block;
  background: gold;
  position: absolute;
  top: -50px;
  left: -50px;
  width: 200px;
  height: 200px;
  z-index: -1;
  border-radius: 100%;
}

}

程序不断突破

2 个答案: