Can you please share how you enter your data? because for me do not print and information for this code.

From line $96$ till the end, the code is not correct. HeadPtr can not be used, it because it is: 'headPtr' is a private member of 'LinkedList'. Anyway the last $20$ lines of this code is broken...

#include

#include

#include

#include

using namespace std;

class Node $\{$

public:

string category;

string line;

Node$*$ next;

Node$($const string& category, const string& line$)$

: category$($category$),$ line$($line$),$ next$($nullptr$)\{\}$

$\}$;

class LinkedList $\{$

private:

Node$*$ headPtr;

public:

LinkedList$()$ : headPtr$($nullptr$)\{\}$

~LinkedList$()$;

void addNode$($const string& category, const string& line$)$;

void displayList$()$;

vector toVector$()$;

$\}$;

LinkedList::~LinkedList$()\{$

while $($headPtr $!=$ nullptr$)\{$

Node$*$ temp $=$ headPtr;

headPtr $=$ headPtr$->$next;

delete temp;

$\}$

$\}$

void LinkedList::addNode$($const string& category, const string& line$)\{$

Node$*$ newNode $=$ new Node$($category$,$ line$)$;

if $($headPtr $==$ nullptr $||$ category $$ headPtr$->$category $||$

$($category $==$ headPtr$->$category && line headPtr$->$line$))\{$

newNode$->$next $=$ headPtr;

headPtr $=$ newNode;

return;

$\}$

Node$*$ curPtr $=$ headPtr;

while $($curPtr$->$next $!=$ nullptr &&

$($category $>$ curPtr$->$next$->$category $||$

$($category $==$ curPtr$->$next$->$category && line $>$ curPtr$->$next$->$line$)))\{$

curPtr $=$ curPtr$->$next;

$\}$

newNode$->$next $=$ curPtr$->$next;

curPtr$->$next $=$ newNode;

$\}$

void LinkedList::displayList$()\{$

Node$*$ curPtr $=$ headPtr;

while $($curPtr $!=$ nullptr$)\{$

cout $$ curPtr$->$line $$ endl;

curPtr $=$ curPtr$->$next;

$\}$

$\}$

vector LinkedList::toVector$()\{$

vector result;

Node$*$ curPtr $=$ headPtr;

while $($curPtr $!=$ nullptr$)\{$

result.push$\_$back$($curPtr$->$category$)$;

result.push$\_$back$($curPtr$->$line$)$;

curPtr $=$ curPtr$->$next;

$\}$

return result;

$\}$

int main$()\{$

LinkedList categories$[5]$;

string filename $="/$input$.$txt$"$; $//$ Change this to your input file name

$//$ cout $$ "Enter the file name: $"$;

$//$ cin $>>$ filename;

ifstream inputFile$($filename$)$;

if $(!$inputFile$)\{$

cerr $$ "Error opening file $"$ filename $$ endl;

return $1$;

$\}$

string category, line;

while $($getline$($inputFile$,$ line$))\{$

if $($line$.$empty$())$ continue;

int delimiterIndex $=$ line.find$(\text{'}$:$\text{'})$;

if $($delimiterIndex $==$ string::npos$)$ continue;

category $=$ line.substr$(0,$ delimiterIndex$)$;

line $=$ line.substr$($delimiterIndex $+1)$;

for $($int i $=0$; i $<mtext></mtext><mn>5</mn>$; i$++)\{$

if $($categories$[$i$].$headPtr && categories$[$i$].$headPtr$->$category $==$ category$)\{$

categories$[$i$].$addNode$($category$,$ line$)$;

break;

$\}$

$\}$

$\}$

inputFile.close$()$;

for $($int i $=0$; i $<mtext></mtext><mn>5</mn>$; i$++)\{$

if $($categories$[$i$].$headPtr$)\{$

cout $$ categories$[$i$].$headPtr$->$category :$"$ endl;

vector lines $=$ categories$[$i$].$toVector$()$;

for $($int j $=1$; j $$ lines.size$()$; j $+=2)\{$

cout lines$[$j$]$ endl;

$\}$

$\}$

$\}$

return $0$;

$\}$