Question

Write a C++ program to manage a list of inventory items using a linked list. Operations should include adding a new inventory item at the end of the list, adding a new inventory item at the beginning of the list, removing an inventory item from the beginning of the list, removing an inventory item from the end of the list, removing an inventory item by name, and display the current list of inventory items. Allow the user an option to exit.

Answer 1

#include<iostream>

#include<stdlib.h>

using namespace std;

class Inventory

{

public:

string name;

Inventory* next;

};

class List:public Inventory

{

Inventory *first,*last;

public:

List()

{

first=NULL;

last=NULL;

}

void insert(int choice);

void deleteInventory(int choice);

void display();

int search(string value);

};

void List::insert(int choice)

{

Inventory *prev,*cur;

prev=NULL;

cur=first;

string n;

Inventory *temp=new Inventory;

cout<<"\nEnter an Inventory name:";

cin>>n;

temp->name=n;

temp->next=NULL;

switch(choice)

{

case 1:

temp->next=first;

first=temp;

break;

case 2:

last->next=temp;

last=temp;

break;

}

}

void List::deleteInventory(int choice)

{

Inventory *prev=NULL,*cur=first;

int count=1,pos;

string name;

switch(choice)

{

case 1:

if(first!=NULL)

{

cout<<"\nDeleted Element is "<<first->name;

first=first->next;

}

else

cout<<"\nNot Able to Delete";

break;

case 2:

while(cur!=last)

{

prev=cur;

cur=cur->next;

}

if(cur==last)

{

cout<<"\nDeleted Element is: "<<cur->name;

prev->next=NULL;

last=prev;

}

else

cout<<"\nNot Able to Delete";

break;

case 3:

cout<<"\nEnter the name of Inventory:";

cin>>name;

pos = this->search(name);

if (pos == -1) {

cout<<"\nDid not found Inventory:";

break;

}

while(count!=pos)

{

prev=cur;

cur=cur->next;

count++;

}

if(count==pos)

{

cout<<"\nDeleted Element is: "<<cur->name;

prev->next=cur->next;

}

else

cout<<"\nNot Able to Delete";

break;

}

}

void List::display()

{

Inventory *temp=first;

if(temp==NULL)

{

cout<<"\nList is Empty";

}

while(temp!=NULL)

{

cout<<temp->name;

cout<<"-->";

temp=temp->next;

}

cout<<"NULL";

}

int List::search(string value)

{

int pos=0;

bool flag=false;

if(first==NULL)

{

cout<<"List is Empty";

return -1;

}

Inventory *temp;

temp=first;

while(temp!=NULL)

{

pos++;

if(temp->name==value)

{

flag=true;

return pos;

}

temp=temp->next;

}

if(!flag)

{

return -1;

}

}

int main()

{

List l;

int ch;

while(1)

{

cout<<"\n**** MENU ****";

cout<<"\n1:Add Inventory at End\n2:Add Inventory at Beginning\n3:Remove Inventory from End\n4:Remove Inventory from Beginning\n5:Remove Inventory by name\n6: Display Inventories\n7:EXIT\n";

cout<<"\nEnter Your Choice:";

cin>>ch;

switch(ch)

{

case 1:

l.insert(2);

break;

case 2:

l.insert(1);

break;

case 3:

l.deleteInventory(2);

break;

case 4:

l.deleteInventory(1);

break;

case 5:

l.deleteInventory(3);

break;

case 6:

l.display();

break;

case 7:

return 0;

}

}

return 0;

}