Question

我差不多完成了一个程序，但是我需要按升序对链表进行排序，并且我已经尝试了几个小时但无法弄明白，但程序的其余部分仍然有效。假设生成6个随机数并将它们存储在链表中并每次输出它直到它达到6个数字然后它停止然后删除每个元素直到它们全部被删除。但是假设在输出数字时对数字进行排序。它将节点存储在push_sorted函数中，所以我认为这是排序函数将要进行的，但我再也无法弄清楚如何对链表进行排序。无论如何感谢任何帮助，这是我的整个计划...

#include <iostream>
#include <ctime>
#include <cstdlib>
#include "SortedLinkedList.h"
#include <algorithm>
#include <list>
#include <array>

using namespace std;

struct node
{
    int data;
    node *next;
};

node *head = NULL;

void push_sorted(int value)
{
    node *newNode = new node;
    newNode->data = value;
    newNode->next = NULL; 

    if(head == NULL)
    {
        head = newNode;
    }
    else
    {
        node *newNode_2 = head;
        while(newNode_2->next != NULL)
        {
            newNode_2 = newNode_2-> next;
        }
        newNode_2->next = newNode;
    }
}

void pop_front()
{
    node *temp;
    temp = head;
    head = head->next;
    free(temp);
}

void pop_back(int pos)
{
  node *temp =head;
  struct node *t = NULL;
  if(head->next==NULL)
  {
    free(head);
    head=NULL;
  }
  else
  {
     while(temp->next != NULL)
     {
        t=temp;
        temp=temp->next;
     }
     free(t->next);
     t->next=NULL; 
  }    


}



bool isEmpty(int count)
{
    if(count == 0)
    {
        return false;
    }

    else
    {
        return true;
    }

}

void print()
{
    node* current = head;
    while(current != NULL)
    {
        cout << current-> data << " ";
        current = current->next;
    }
    cout << endl;
}
int main()
{
    int pos = 4;
    int count  = 6;
    const int NUMS = 6;     //insert elements into the sorted linked list in an ascending order
    const int RANGE = 21;   //each element is in the range [-10, 10]
    /*SortedLinkedList mylist;*/
    srand(time(0));
    for (int i = 0; i < NUMS; i++)
    {
        int data = (rand() % RANGE) - 10;
        cout << "Adding " << data << " to the sorted linked list: " << endl;
        push_sorted(data);
        print();
    }

    while ((isEmpty(count) == true))
    {
        cout << "Removing from front..." << endl;
        pop_front();
        print();
        count --;
        /*if (count == 1)
        {
            break;
        }*/
        cout << "Removing from back..." << endl;
        pop_back(pos);
        print();
        count --;
        pos-= 2;
    }
    system("pause");
    return 0;
}

Answer 1

您应该按照建议使用std::list。但假设您出于其他原因需要它，您可以修改函数以比较值并交换节点，如下所示：

void push_sorted(int value)
{
    node *n = new node;
    n->data = value;
    n->next = NULL;
    if (!head)
    {
        head = n;
    }
    else
    {
        node *cursor = head;
        if (head->data > value)
        {
            node *temp = head;
            head = n;
            n->next = temp;
            return;
        }
        while (cursor->next)
        {
            if (cursor->next->data > value)
            {
                node *temp = cursor->next;
                cursor->next = n;
                n->next = temp;
                return;
            }
            cursor = cursor->next;
        }
        cursor->next = n;
    }
}

或者只是使用

std::list<int> lst; 
lst.push_back(data);
lst.sort();

您也可以考虑std::vector大部分时间执行std::list。

对链接列表进行排序

1 个答案: