Data Structure Program

http://www.cplusplus.happycodings.com/Data_Structures/index.html

Stack implementation as a class.

# include<iostream.h>
# include<process.h>
# include<conio.h>
# define SIZE 20

class stack
{
int a[SIZE];
int tos; // Top of Stack
public:
stack();
void push(int);
int pop();
int isempty();
int isfull();
};
stack::stack()
{
tos=0; //Initialize Top of Stack
}

int stack::isempty()
{
return (tos==0?1:0);
}
int stack::isfull()
{
return (tos==SIZE?1:0);
}

void stack::push(int i)
{
if(!isfull())
{
a[tos]=i;
tos++;
}
else
{
 cerr<<"Stack overflow error !
Possible Data Loss !";
}
}
int stack::pop()
{
if(!isempty())
{
return(a[--tos]);
}
else
{
cerr<<"Stack is empty! What to pop...!";
}
return 0;
}

void main()
{
stack s;
int ch=1,num;
while(ch!=0)
{
cout<<"Stack Operations Mani Menu
1.Push
2.Pop
3.IsEmpty
4.IsFull
0.Exit

";
cin>>ch;
switch(ch)
{
case 0:
exit(1); //Normal Termination of Program
case 1:
cout<<"Enter the number to push";
cin>>num;
s.push(num);
break;
case 2:
cout<<"Number popped from the stack is: "<<s.pop()<<endl;
break;
case 3:
(s.isempty())?(cout<<"Stack is empty.
"):(cout<<"Stack is not empty.
");
break;
case 4:
(s.isfull())?(cout<<"Stack is full.
"):(cout<<"Stack is not full.
");
break;
default:
cout<<"Illegal Option.
Please try again
";
}
}//end of while
getch();
}


=====================================================================================================

Queue implementation using linked list

#include <iostream.h>
#include <conio.h>
#include <stdlib.h>

struct node
 {  char name[20];
    int age;
    float height;
    node *nxt;
 };
node *start_ptr=NULL;

int main()
{

  void push ();
  void pop();
  char ch;
  clrscr();
  cout<<"Queue
";
  cout<<"-----";

  do
  {
   cout<<"
Select an operation";
   cout<<"
u->push
";
   cout<<"o->pop
";
   cout<<"e->exit
";

   cin>>ch;

   switch(ch)
   {
    case 'u':
                     push();
                     break;
    case 'o':
                     pop();
                     break;
    case 'e':
                     exit(0);
   }
   }while(ch!='e');

                return 0;

}

void pop()
{
 node *temp1,*temp2;
 if(start_ptr==NULL)
   cout<<"The list is empty
";
 else
  {
   temp1=start_ptr;
   temp2=temp1;
  while(temp1->nxt!=NULL)
   {
    temp2=temp1;
    temp1=temp1->nxt;
   }
  if(temp1==temp2)
    {
     cout<<temp1->name<<",";
     cout<<temp1->age<<", ";
     cout<<temp1->height;
     start_ptr=NULL;
    }
  else
    {
     cout<<temp1->name<<", ";
     cout<<temp1->age<<", ";
     cout<<temp1->height;
     temp2->nxt=NULL;
     delete temp1;
    }
 }
}

void push ()
 {
    node *temp;

    temp = new node;
    cout << "Please enter the name of the person: ";
    cin >> temp->name;
    cout << "Please enter the age of the person: ";
    cin >> temp->age;
    cout << "Please enter the height of the person: ";
    cin >> temp->height;
    if (start_ptr == NULL)
                {
                 temp->nxt=NULL;
                 start_ptr = temp;
                }
    else
                {
      temp->nxt=start_ptr;
      start_ptr=temp;

                }
  }







=====================================================
Single linked list

#include<iostream.h>
#include<conio.h>
#include<stdlib.h>


class list
{
struct node
{
int data;
node *link;
}*p;
public:
void inslast(int);
void insbeg(int);
void insnext(int,int);
void delelement(int);
void delbeg();
void dellast();
void disp();
int seek(int);
list(){p=NULL;}
~list();
};

void list::inslast(int x)
{
node *q,*t;
if(p==NULL)
{
p=new node;
p->data=x;
p->link=NULL;
}
else
{
q=p;
while(q->link!=NULL)
q=q->link;
t=new node;
t->data=x;
t->link=NULL;
q->link=t;
}
cout<<"
 Inserted successfully at the end..
";
disp();
}

void list:: insbeg(int x)
{
node *q;
q=p;
p=new node;
p->data=x;
p->link=q;
cout<<"
 Inserted successfully at the begining..
";
disp();
}


void list::delelement(int x)
{
node *q,*r;
q=p;
if(q->data==x)
{
p=q->link;
delete q;
return;
}
r=q;
while(q!=NULL)
{
if(q->data==x)
{
r->link=q->link;
delete q;
return;
}
r=q;
q=q->link;
}
cout<<"
 Element u entered   "<<x<<"    is not found..
";
}

void list:: delbeg()
{
cout<<"
 The list before deletion:
";
disp();
node *q;
q=p;
if(q==NULL)
{
cout<<"
 No data is present..
";
return;
}
p=q->link;
delete q;
return;
}


void list:: dellast()
{
cout<<"
 The list before deletion:
";
disp();
node *q,*t;
q=p;
if(q==NULL)
{
cout<<"
 There is no data in the list..
";
return;
}
if(q->link==NULL)
{
p=q->link;
delete q;
return;
}

while(q->link->link!=NULL)
q=q->link;
q->link=NULL;
return;
}

list::~list()
{
node *q;
if(p==NULL) return;
while(p!=NULL)
{
q=p->link;
delete p;
p=q;
}
}

void list::disp()
{
node *q;
q=p;
if(q==NULL)
{
cout<<"
 No data is in the list..
";
return;
}
cout<<"
 The items present in the list are :
";
while(q!=NULL)
{
cout<<" "<<q->data;
q=q->link;
}
}

void list :: insnext(int value,int position)
{
node *temp,*temp1;
temp=p;
if(temp1==NULL)
{
temp1= new node;
temp1->data=value;
temp1->link=NULL;
p=temp1;
return;
}
for(int i=0;((i<position)&&(temp->link!=NULL)) ;i++)
{
if(i==(position-1))
{
temp1= new node;
temp1->data= value;
temp1->link=temp->link;
temp->link=temp1;
}
temp=temp->link;
}
//cout<<"
 Inserted successfully at the position.."<<position;
disp();
}


int list::seek(int value)
{
node *temp;
temp=p;
int position=0;
while(temp!=NULL)
{
if(temp->data==value)
return position+1;
else
{
temp=temp->link;
position=position+1;
}
}
cout<<"

 Element "<<value<<" not found";
return 0;
}


void main()
{
list l;
int ch,v,p,ps;
do
{
clrscr();
cout<<"
 Operations on List..
";
cout<<"
1.Insertion
2.Deletion
3.Display
4.Seek
5.Exit";
cout<<"
 Enter ur choice:";
cin>>ch;

switch(ch)
{
case 1:
cout<<"
1.Insertion at begining
2.Insertion at the end
";
cout<<"3.Insertion after the mentioned position
";
cout<<"
 Enter ur choice:";
cin>>ps;
cout<<"
 Enter the value to insert:";
cin>>v;
switch(ps)
{
case 1:
l.insbeg(v);
break;
case 2:
l.inslast(v);
break;
case 3:
cout<<"
 Enter the position to insert the value:";
cin>>p;
l.insnext(v,p);
break;

default:
cout<<"
 The choice is invalid
";
return;
}
break;

case 2:
cout<<"
1.Delete the first element
2.Delete the last element";
cout<<"
3.Enter the element to delete from the list";
cout<<"
 Enter ur choice:";
cin>>ps;
switch(ps)
{
case 1:
l.delbeg();
cout<<"
 The list after deletion:
";l.disp();
break;
case 2:
l.dellast();
cout<<"
 The list after deletion:
";l.disp();
break;
case 3:
l.disp();
cout<<"
 Enter the element to delete : ";
cin>>v;
l.delelement(v);
cout<<"
 The list after deletion:
";l.disp();
break;

default:
cout<<"
 The option is invalid...
";
break;
}
break;

case 3:
l.disp();
break;

case 4:
l.disp();
cout<<"
 Enter the element to search:";
cin>>v;
cout<<"
 The position of the element "<< v<<"  is "<<l.seek(v);
getch();
break;

case 5:
exit(1);

default:
cout<<"
 The option is invalid...
";
return;
}
getch();
}while(ch!=5);
getch();
return;
}