Question

Chapter 18 Lab –

Design and code your own LIFO Stack using single liked list to hold a list of integers. Use the C++ “struct” structure to create your SLL nodes. Node position numbering should start with one.

Your program should include the main program to test and demonstrate one function for each Stack operations including:

InitStack – Initialize LIFO Stack

PushStack – Add an item to top of Stack at

PrintStack – Print out the Stack items

PopStack – Remove and return top item from Stack

TopStack – Returns the first item on Stack without deleting it

EmptyStack – Checks for empty Stack condition (TRUE/FALLS)

ClearStack – Delete all items from Stack

Answer 1

#include<iostream>
using namespace std;

//creating list node
struct node{
   int data;
   node* next;
};

//InitStack – Initialize LIFO Stack
void InitStack(node *& start, node *&end)
{
start=NULL;
end=NULL;
}

//PushStack – Add an item to top of Stack
void PushStack(node *& start, node *&end, int data)
{
   node* temp= new node;
   temp->data=data;
   temp->next=NULL;
   //pushing element in empty stack
   if (start==NULL)
   {   
       start=temp;
       end=temp;
       }
   //pushing element in existing stack
   else if (start!=NULL)
   {
   temp->next=start;
   start=temp;
   }
}

//PrintStack – Print out the Stack items
void PrintStack(node *& start)
{
node* temp=new node;
temp=start;
   if (temp==NULL)
   {
   cout<<"Stack is empty"<<endl;
   }
   else
   {
       cout<<"Stack items are: "<<endl;
       while(temp!=NULL)
       {
           cout<<temp->data<<" --> "<<endl;
           temp=temp->next;       }
   }
}

//PopStack – Remove and return top item from Stack
void PopStack(node *&start, node *& end)
{
   if (start==NULL)
   {
       cout<<"Stack is empty"<<endl;
   }
   else if (start==end)
   { cout<<"Element popped from the stack: "<<start->data<<endl;
   delete start;
       start=NULL;
       end=NULL;
   }
   else
   {
       node* temp=new node;
       temp=start;
       start=start->next;
       cout<<"Element popped from the stack: "<<temp->data<<endl;
       delete temp;
   }
}

//TopStack – Returns the first item on Stack without deleting it
void TopStack(node *& start)
{
   node* temp=new node;
   temp=start;
   if (temp==NULL)
   {
   cout<<"Stack is empty"<<endl;
}   
   else
   {
   cout<<"Element in the top of the stack: "<<temp->data<<endl;
}
}

//EmptyStack -Checks for empty Stack condition (TRUE/FALSE)"
bool EmptyStack(node *&start)
{
   if(start==NULL)
   return true;
   else
   return false;
}

//ClearStack – Delete all items from Stack
void ClearStack(node *& start)
{
   node* temp=new node;
   if (start==NULL)
   {
   cout<<"Stack is empty"<<endl;  
   }
   else
   {
   while(start!=NULL)
   {
   temp=start;
   start=start->next;
   delete temp;
}
cout<<"Stack is deleted"<<endl;
}
}

int main()
{
   node* start;
   node* end;
int choice;
while(1){
cout<<"1. InitStack – Initialize LIFO Stack"<<endl;
   cout<<"2. PushStack – Add an item to top of Stack at"<<endl;
   cout<<"3. PrintStack – Print out the Stack items"<<endl;
   cout<<"4. PopStack – Remove and return top item from Stack"<<endl;
   cout<<"5. TopStack – Returns the first item on Stack without deleting it"<<endl;
   cout<<"6. EmptyStack – Checks for empty Stack condition (TRUE/FALSE)"<<endl;
   cout<<"7. ClearStack – Delete all items from Stack"<<endl;
   cout<<"8. Exit."<<endl;
   cout<<"Enter your choice : ";
   cin>>choice;
   switch(choice)
{
   case 1:
       InitStack(start,end);
       break;
case 2:
       int element;
       cout<<"Enter an element: ";
           cin>>element;
           PushStack(start,end,element);
           break;
       case 3:
           PrintStack(start);
           break;
       case 4:
           PopStack(start,end);
           break;
       case 5:
           TopStack(start);
           break;
       case 6:
           if(EmptyStack(start))
               cout<<endl<<"Yes. Stack is empty";
           else
               cout<<endl<<"No. Stack is not empty";
           break;      
       case 7:
           ClearStack(start);
       break;
       case 8:
           exit(0);
   }
}
       return 0;  
}