$//$Main$.$cpp

#include "SinglyLinkedList.h$"$

#include

#include

#include

using namespace std;

int main$()\{$

LinkedList list;

list.append$($new Person$(1,$ "John", "Doe"$))$;

list.append$($new Person$(2,$ "Jane", "Doe"$))$;

list.append$($new Person$(3,$ "Paul", "Harvey"$))$;

Node$*$ searchResult $=$ listSearch$($&list, $3)$;

if $($searchResult$)\{$

cout $$ "listSearch found: $"$ searchResult$->$person$->$descriptor$()$ endl;

$\}$ else $\{$

cout $$ "listSearch did not find the key." $$ endl;

$\}$

string descriptor $=$ listDescriptor$($&list$)$;

cout $$ "listDescriptor output:

$"$ descriptor;

Node$*$ current $=$ list.head;

while $($current$)\{$

Node$*$ next $=$ current$->$next;

delete current$->$person;

delete current;

current $=$ next;

$\}$

return $0$;

$\}$

$//$singleylinkedlist$.$h

#ifndef SINGLY$\_$LINKED$\_$LIST

#define SINGLY$\_$LINKED$\_$LIST

using namespace std;

class Node $\{$

public:

Person$*$ person; $//$ Pointer to a Person instance

Node$*$ next; $//$ Pointer to the next Node instance

Node$($Person$*$ p $=$ nullptr$)$ : person$($p$),$ next$($nullptr$)\{\}$

$\}$;

class LinkedList $\{$

public:

Node$*$ head; $//$ Pointer to the head of the linked list

Node$*$ tail; $//$ Pointer to the tail of the linked list

LinkedList$()$ : head$($nullptr$),$ tail$($nullptr$)\{\}$

void append$($Person$*$ p$)\{$

Node$*$ newNode $=$ new Node$($p$)$;

if $(!$head$)\{$

head $=$ newNode;

tail $=$ newNode;

$\}$ else $\{$

tail$->$next $=$ newNode;

tail $=$ newNode;

$\}$

$\}$

$\}$;

Node$*$ listSearch$($LinkedList$*$ list, const int key$)\{$

Node$*$ current $=$ list$->$head;

while $($current$)\{$

if $($current$->$person$->$id $==$ key$)\{$

return current;

$\}$

current $=$ current$->$next;

$\}$

return nullptr; $//$ Key not found

$\}$

string listDescriptor$($LinkedList$*$ list$)\{$

ostringstream oss;

Node$*$ current $=$ list$->$head;

while $($current$)\{$

oss $$ current$->$person$->$descriptor$()$ endl;

current $=$ current$->$next;

$\}$

return oss.str$()$;

$\}$

#endif