从文本文件中将整数读入一个简单的链表。 然后对整数列表进行冒泡排序并读出到另一个文件

Question

Read integers into a simple linked list from text file. Then bubblesort the list of integers and read out to another file. Right now I am reading into the main but I am trying to overload the extraction operator to read it in and I am not sure how to go about that. My Bubblesort function is also causing alot of issues. Its telling me the function cannot be overloaded and the node identifier is undeclared amongst other things. Any help would be greatly appreciated

Main file

#include <iostream>
#include <cstdlib>
#include <iomanip>
#include <fstream>
#include "bubble.h"

using namespace std;
struct nodeType
{
    int info;
    nodeType* link;
};

node *head_ptr = NULL;
void Display();
void list_clear(nodeType*& head_ptr);
void list_copy(const nodeType* source_ptr, nodeType*&head_ptr, nodeType*&tail_ptr);
Bubblesort();


int main()
{
    ifstream datld;
    ofstream outld;

    Bubble D3;

    datld.open ("infile2.txt");
    if (!datld)
    {
        cout << "failure to open data.txt" << endl;
        system ("pause");
        return 1;
    }

    datld >> D3;

    while(datld)
    {
        cout << D3<< endl;
        datld >> D3;
    }

    system("pause");
    return 0;

    Bubblesort();
}


void Bubblesort()
{
    node* curr = head_ptr;
    int count = 0;
    while(curr!=NULL)
    {
        count++;
        curr = curr->NEXT;
    }
    for(int i = count ; i > 1 ; i-- )
    {
        node *temp, *swap1;
        swap1 = HEAD;
        for(int j = 0 ; j < count-1 ; j++ )
        {
            if(swap1->DATA > swap1->NEXT->DATA)
            {
                node *swap2 = swap1->NEXT;
                swap1->NEXT = swap2->NEXT;
                swap2->NEXT = swap1;
                if(swap1 == HEAD)
                {
                    HEAD = swap2;
                    swap1 = swap2;
                }
                else
                {
                    swap1 = swap2;
                    temp->NEXT = swap2;
                }
            }
            temp = swap1;
            swap1 = swap1->NEXT;
        }
    }
}


void list_clear(nodeType*& head_ptr)
//Library facilities used:cstdlib
{
    nodeType * removeptr;
    while(head_ptr!=NULL)
    {
        removeptr=head_ptr;
        head_ptr=head_ptr->link;
        delete removeptr;
    }
}

void list_copy(const nodeType* source_ptr, nodeType*&head_ptr, nodeType*&tail_ptr)
{
    nodeType* temp;// to allocate new nodes
    head_ptr=NULL;
    tail_ptr=NULL;

    if(source_ptr==NULL)
        return;

    head_ptr=new nodeType;
    head_ptr->link=NULL;
    head_ptr->info=source_ptr->info;
    tail_ptr=head_ptr;
    source_ptr=source_ptr->link;

    while(source_ptr!=NULL)
    {
        temp = new nodeType;
        temp->link=NULL;
        temp->info =source_ptr-> info;
        tail_ptr->link=temp;
        tail_ptr = tail_ptr->link;
        source_ptr = source_ptr->link;
    }
}

Header file

#include <iostream>
#include <iomanip>
#include <fstream>
#include <cstdlib>
using namespace std;

class Bubble
{
private:
    int manynodes;
public:
    Bubble() { }

    void Bubblesort();

    friend ostream &operator<<( ostream &output, const Bubble &D )
    {
        output << D.manynodes;
        return output;
    }

    friend istream &operator>>( istream  &input, Bubble &D )
    {
        input >> D.manynodes;
        return input;
    }
};

Answer 1

• Your extraction operator looks fine. I don't know if it really does what you need, but that's another issue.
• You are declaring function Bubblesort() twice: first in the header file as void Bubblesort() , then in the main file as just Bubblesort() (this should at least give you a warning that it is considered to mean int Bubblesort() ). You cannot overload a function just on the return value, hence the error.
• Indeed, you are using a type called node in several places, but you have not declared nor defined it anywhere.