How to implement Binary Search Tree and show output as Inorder, Preorder and Post Order?

#include<conio.h>
#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
using namespace std;
struct node
{
struct node *lchild,*rchild;
int info;
}*root;
void find(int,struct node **,struct node **);
void insert(int);
void del(int);
void case_a(struct node*,struct node*);
void case_b(struct node*,struct node*);
void case_c(struct node*,struct node*);
void preorder(struct node *);
void inorder(struct node *);
void postorder(struct node *);
main()
{
int choice,num;
root=NULL;
while(1)
{
cout<<"\n";
cout<<"1.INSERT"<<endl;
cout<<"2. DELETE"<<endl;
cout<<"3. INORDER TRAVERSAL"<<endl;
cout<<"4. PREORDER TRAVERSAL"<<endl;
cout<<"5. POSTORDER TRAVERSAL"<<endl;
cout<<"6. QUIT"<<endl;
cout<<"enter your choice"<<endl;
cin>>choice;
switch(choice)
{
case 1:
cout<<"Enter the number to be inserted"<<endl;
cin>>num;
insert(num);
break;
case 2:
cout<<"Enter the number to be deleted"<<endl;
cin>>num;
del(num);
break;
case 3:
inorder(root);
break;
case 4:
preorder(root);
break;
case 5:
postorder(root);
break;
case 6:
exit(1);
default:
cout<<"WRONG CHOICE"<<endl;
}
}
}
void find(int item,struct node**par,struct node**loc)
{
struct node *ptr,*ptrsave;
if(root==NULL)
{
*loc=NULL;
*par=NULL;
return;
}
if(item==root->info)
{
*loc=root;
*par=NULL;
return;
}
if(item<root->info)
ptr=root->lchild;
else
ptr=root->rchild;
ptrsave=root;
while(ptr!=NULL)
{
if(item==ptr->info)
{
*loc=ptr;
*par=ptrsave;
return;
}
ptrsave=ptr;
if(item<ptr->info)
ptr=ptr->lchild;
else
ptr=ptr->rchild;
}
*loc=NULL;
*par=ptrsave;
}
void insert(int item)
{
struct node *tmp,*parent,*location;
find(item,&parent,&location);
if(location!=NULL)
{
cout<<"Item Is Already Present"<<endl;
return;
}
tmp=new(struct node);
tmp->info=item;
tmp->lchild=NULL;
tmp->rchild=NULL;
if(parent==NULL)
root=tmp;
else
if(item<parent->info)
parent->lchild=tmp;
else
parent->rchild=tmp;
}
void del(int item)
{
struct node *parent,*location;
if(root==NULL)
{
cout<<"TREE EMPTY"<<endl;
return;
}
find(item,&parent,&location);
if(location==NULL)
{
cout<<"item not presented in the tree"<<endl;
return;
}
if(location->lchild==NULL&&location->rchild==NULL)
case_a(parent,location);
if(location->lchild!=NULL&&location->rchild==NULL)
/*case_b(parent,location);
if(location->lchild==NULL&&location->rchild!=NULL)
case_b(parent,location);
if(location->lchild!=NULL&&location->rchild!=NULL)
case_c(parent,location);*/
free(location);
}
void case_a(struct node *par,struct node *loc)
{
if(par==NULL)
root=NULL;
else
if(loc==par->lchild)
par->lchild=NULL;
else
par->rchild=NULL;
}
void case_b(struct node *par,struct node *loc)
{
struct node *child;
if(loc->lchild!=NULL)
child=loc->lchild;
else
child=loc->rchild;
if(par==NULL)
root=child;
else
if(loc==par->lchild)
par->lchild=child;
else
par->rchild=child;
}
void case_c(struct node *par,struct node *loc)
{
struct node *ptr,*ptrsave,*suc,*parsuc;
ptrsave=loc;
ptr=loc->rchild;
while(ptr->lchild!=NULL)
{
ptrsave=ptr;
ptr=ptr->lchild;
}
suc=ptr;
parsuc=ptrsave;
if(suc->lchild==NULL&&suc->rchild==NULL)
case_a(parsuc,suc);
else
case_b(parsuc,suc);
if(par==NULL)
root=suc;
else
if(loc==par->lchild)
par->lchild=suc;
else
par->rchild=suc;
suc->lchild=loc->lchild;
suc->rchild=loc->rchild;
}
void preorder(struct node *ptr)
{
if(root==NULL)
{
cout<<"TREE IS EMPTY"<<endl;
return;
}
if(ptr!=NULL)
{
cout<<ptr->info<<"\t";
preorder(ptr->lchild);
preorder(ptr->rchild);
}
}
void inorder(struct node *ptr)
{
if(root==NULL)
{
cout<<"TREE IS EMPTY"<<endl;
return;
}
if(ptr!=NULL)
{
inorder(ptr->lchild);
cout<<ptr->info<<"\t";
inorder(ptr->rchild);
}
}
void postorder(struct node *ptr)
{
if(root==NULL)
{
cout<<"TREE IS EMPTY"<<endl;
return;
}
if(ptr!=NULL)
{
postorder(ptr->lchild);
postorder(ptr->rchild);
cout<<ptr->info<<"\t";
}
}

How to implement Stack by Array in C++?

#include<iostream>
#include<conio.h>
#include<stdio.h>
//#include<stack>
using namespace std;


#define max 5
int Stack_Array[max];
int top=-1;
void push();
void pop();
void display();

main()
{
int choice;
while(1)
{
cout<<"1: Push"<<endl;
cout<<"2: Pop"<<endl;
cout<<"3: Display"<<endl;
cout<<"4:Quit"<<endl;
cin>>choice;

switch(choice)
{
case 1:
push();
break;

case 2:
pop();
break;

case 3:
display();
break;

case 4:
return 0;;

default:
cout<<"Wrong Choice"<<endl;

}  //end of switch
}  //end of while
}   //end of main

void push()
{
int pushed_item;
if(top==(max-1))
    cout<<"Stack_Array Overflow"<<endl;
else
{
    cout<<"Enter the item to be pushed in Stack_Array:"<<endl;
    cin>>pushed_item;
    top=top+1;
    Stack_Array[top]=pushed_item;

}
}


void pop()
{
if(top==-1)
    cout<<"Stack_Array Underflow"<<endl;
else
{
    cout<<"Poped element is:"<<Stack_Array[top]<<endl;
    top=top-1;
}
}


void display()
{
int i;
if(top==-1)
    cout<<"Stack_Array Empty"<<endl;
else
{
    cout<<"Stack_Array element:"<<endl;
    for(i=top;i>=0;i--)
    cout<<Stack_Array[i]<<endl;
}
}

How to implement Circular Queue By Linklist?

//Circular Queue Through Linklists
#include<iostream>
#define SIZE 100
#include<conio.h>
using namespace std;
struct circularque
{
  int data;
  struct circularque *next;
}*f=NULL,*r=NULL,*n,*temp,*temp1;

void insert();
void delet();
void display();

int main()
{
  int ch;
  do
  {
     cout<<"\n\n\tMain Menu";
     cout<<"\n****************************";
     cout<<"\n1. Insert\n2. Delete\n3. Display\n4. Exit\n\nEnter Your Choice: ";
     cin>>ch;
     switch(ch)
     {
    case 1:
      insert();
      display();
      break;
    case 2:
      delet();
      break;
    case 3:
    display();
      break;
      case 4:
    default:
      cout<<"\n\nWrong Choice!!! Try Again.";
     }
  }while(ch!=4);
  return 0;
}

void insert()
{
  n=new circularque[sizeof(circularque)];
  cout<<"\nEnter the Element: ";
  cin>>n->data;
  if(f==NULL)
  {
      f=n;
  }
  else
  {
      r->next=n;
  }
  r=n;
  r->next=f;
}
void delet()
{
  int x;
  temp=f;
  if(f==NULL)
  {
      cout<<"\nCircular Queue Empty!!!";
  }
  else
  {
     if(f==r)
     {
       x=f->data;
       delete(temp);
       f=NULL;
       r=NULL;
     }
     else
     {
    x=temp->data;
    f=f->next;
    r->next=f;
    delete(temp);
     }
     cout<<"\nElement "<<x<<" is Deleted";
     display();
  }
}
void display()
{
  temp=f;
  temp1=NULL;
  if(f==NULL)
  {
    cout<<"\n\nCircular Queue Empty!!!";
  }
  else
  {
    cout<<"\n\nCircular Queue Elements are:\n\n";
    while(temp!=temp1)
    {
       cout<<temp->data<<"  ";
       temp=temp->next;
       temp1=f;
    }
  }
}

How to implemet Linear Queue By Linklist?

#include<iostream>
#include<stdlib.h>
using namespace std;
struct node
{
                int data;
                struct node *next;
}*front=NULL,*rear,*temp;
void ins()
{
                temp=new node;
                cout<<"Enter data:";
                cin>>temp->data;
                temp->next=NULL;       

                if(front==NULL)
                                front=rear=temp;
                else
                {
                                rear->next=temp;
                                rear=temp;
                }
                cout<<"Node has been inserted\n";     
}
void del()
{
                if(front==NULL)
                                cout<<"Queue is empty\n";
                else
                {
                                temp=front;
                                front=front->next;
                                cout<<"Deleted node is "<<temp->data<<"\n";
                                delete(temp);
                }
}
void dis()
{
                if(front==NULL)
                                cout<<"Queue is empty\n";
                else
                {
                                temp=front;
                                while(temp->next!=NULL)
                                {
                                                cout<<temp->data<<"->";
                                                temp=temp->next;
                                }

                                cout<<temp->data;
                }
}
main()
{
                int ch;
                while(1)
                {
                                cout<<"\n*** Menu ***"<<"\n1.Insert\n2.Delete\n3.Display\n4.Exit";
                                cout<<"\n\nEnter your choice(1-4):";
                                cin>>ch;
                                cout<<"\n";

                                switch(ch)
                                {
                                                case 1:  ins();
                                                                break;
                                                case 2: del();
                                                                break;
                                                case 3: dis();
                                                                break;
                                                case 4: exit(0);
                                                                break;
                                                default: cout<<"Wrong Choice!!!";
                                }
                }

                return 0;
}

How to create,insert,delete and reverse Linear Doubly linklist in C++?

//Lab 7 Solution
#include<iostream>
#include<conio.h>
#include<malloc.h>
#include<process.h>
using namespace std;
void create_list();
void display();
void addatbeg( );
void addafter(int);
void del(int);
void rev();
struct node{
       int data;
       struct node *next;
       struct node *prev;
}* start;

int main(){

int choice,n,position,i;
int a;
int b;
start=NULL;
while(1)
{
cout<<"1. Create List"<<endl;
cout<<"2. Display List"<<endl;
cout<<"3. Add at Begining"<<endl;
cout<<"4. Add in middle"<<endl;
cout<<"5. Deletion"<<endl;
cout<<"6. Reverse"<<endl;
cout<<"7. Quit Program"<<endl;


cin>>choice;
switch(choice)
{
case 1:
cout<<"How many Nodes you Want? "<<endl;
cin>>n;
for (i=1;i<=n;i++)
{

create_list();
}
break;
case 2:
display();
break;
case 3:
    

addatbeg();
break;
case 7:
exit(0);
case 4:
    

cout<<"Enter position";
cin>>position;
addafter(position);
break;
case 5:
     int m;
     cout<<"enter Element to be deleted"<<endl;
     cin>>m;
     del(m);
     break;
     case 6:
          rev();
          display();
          break;
     default:
cout<<"Wrong Choice"<<endl;
}
}
getch();
return 0;
}
void create_list()
{
struct node *q,*tmp;
tmp=(node*)malloc(sizeof(struct node));
cout<<"Enter data"<<endl;
cin>>tmp->data;
tmp->next=NULL;
tmp->prev=NULL;
if(start==NULL)
{
tmp->prev=NULL;
start=tmp;
}
else
{
q=start;
while(q->next!=NULL)
q=q->next;
q->next=tmp;
tmp->prev=q;
}
}
void display()
{
struct node *q;
if(start==NULL)
{
cout<<"Empty List"<<endl;
return;
}
else
{
q=start;
while(q!=NULL)
{
cout<<q->data<<"\t";
q=q->next;
}
}
cout<<"\n";
}
void addatbeg()
{
struct node *tmp;
tmp=(node *)malloc(sizeof(struct node));

cout<<"enter data"<<endl;
cin>>tmp->data;
tmp->prev=NULL;
tmp->next=start;
start->prev=tmp;
start=tmp;
}
void addafter(int pos)
{
struct node *tmp, *q;
tmp=(node *)malloc(sizeof(struct node));
int i;
q=start;
for(i=1;i<pos-1;i++)
{
q=q->next;
if(q==NULL)
{
cout<<"There are less elements"<<pos;
return;
}
}
tmp=(node *)malloc(sizeof(struct node));
cout<<"Enter data"<<endl;
cin>>tmp->data;
q->prev=tmp;
tmp->next=q->next;
tmp->prev=q;
q->next=tmp;
}

void del(int data)
{
     struct node *q,*tmp;
     if(start->data==data)
     {
                          tmp=start;
                          start=start->next;
                          start->prev=NULL;
                          free(tmp);
                          return;
                          }
                          q=start;
                          while(q->next!=NULL)
                          {
                                                    if(q->data==data)
                                                    {
                                                                            tmp=q->next;
                                                    q->next=tmp->next;
                                                    tmp->next->prev=q;
                                                    free(tmp);
                                                    return;
                                                    }
                                                    q=q->next;
                                                    }
                                                    if(q->data==data)
                                                    {
                                                                           tmp=q->next;
                                                                          
                                                                           q->next=NULL;
                                                                           free(tmp);
                                                                            return;
                                                                           }
}
void rev()
{
     struct node *p1,*p2;
     p1=start;
     p2=p1->next;
     p1->next=NULL;
     p1->prev=p2;
     while(p2!=NULL)
     {
                    p2->prev=p2->next;
                    p2->next=p1;
                    p1=p2;
                    p2=p2->prev;
                    }
                    start=p1;
}
              
                                                                               

How to create,insert,delete and reverse Doubly Circular linklist in C++?

#include<iostream>
#include<conio.h>
using namespace std;
 struct circular
{
    int i;
    struct circular *front;
    struct circular *back;
};
struct circular *temp;
struct circular *head;
struct circular *p;
struct circular *mid;
struct circular *move;

int cnt=0;


void create(void);
void insert(void);
void display(void);
void del(void);



//Creating a node
void create()
{

   
    head=(struct circular *)malloc(sizeof(struct circular));
    head->back=head;
    head->front=head;

    cout<<"ENETER THE DATA\n";
    cin>>head->i;
    temp=head;

    temp->back=(struct circular *)malloc(sizeof(struct circular));
    temp=temp->back;
    temp->back=head;
    head->front=temp;
cout<<"ENETER THE DATA\n";
    cin>>temp->i;


   
}

//Displaying the list
void display()
{
    p=head;
    cout<<p->i;
    p=p->back;
    while(p!=head)
    {
        cout<<p->i;
        p=p->back;
    }
    cout<<"\n";

}

//Inserting a new node
void insert()
{
    int add,t;

    cout<<"\n\t ENTER ANY NUMBER BETWEEN 1 AND %d\n"<<cnt;
    cin>>add;
    p=head;
    t=1;
    while(t<add)
    {
        p=p->back;
        t++;
    }
    mid=(struct circular *)malloc(sizeof(struct circular));
    cout<<"\n\n\nENETER THE DATA\n";
    cin>>mid->i;

    mid->back=p->back;
    p->back=mid;
    p->back->front=mid;
    mid->front=p;

}

//Deleting a node
void del(void)
{
    int add,t;

    cout<<"\n\n\t ENTER ANY NUMBER BETWEEN 1 AND %d\n"<<cnt;
    cin>>add;
    p=head;
    t=1;
    while(t<add-1)
    {
        p=p->back;
        t++;
    }
  
    mid=p->back;
    p->back=mid->back;
    mid->back->front=p;
    free(mid);
}


//Calling in main()
int main()
{
    int ch=0;
    while(ch!=5)
    {
        cout<<"\n1.CREATE";
        cout<<"\n2.INSERT";
        cout<<"\n3.DELETE";
        cout<<"\n4.DISPLAY";
        cout<<"\n5.EXIT\n";
        cin>>ch;


        if(ch==1)
        {
            create();
            cnt++;
            cnt++;
        }

        if(ch==2)
        {
            insert();
            cnt++;
        }
        if(ch==3)
        {
            del();
            cnt--;
        }

        if(ch==4)
        {
            display();
        }

        if(ch==5)
        {
            break;
        }
    }
}

How to create,insert,delete and reverse Signly Circular linklist in C++?

//Implementation of Circular List
#include<conio.h>
#include<iostream>
#include<malloc.h>
using namespace std;
void creation();
void traversing();
void addatbeg();
void addafter(int, int);
void deletion(int);
struct node{
    int info;
    node *link;
   
}*last;
int n;
int main()
{
    last = NULL;
    int ch;
    while(1)
    {
        cout<<"1.Creation";
        cout<<endl;
        cout<<"2.Traversing";
        cout<<endl;
        cout<<"3.Insertion at start";
        cout<<endl;
        cout<<"4. Insertion any Where"<<endl;
        cout<<"5.Deletion";
        cout<<endl;
        cout<<"6.exit";
        //cout<<endl;
        cout<<"Enter Your Choice";
        cin>>ch;
   
    switch(ch)
    {
        case 1:
            int n;
            cout<<"enter number of nodes";
            cin>>n;
            for(int i=0;i<n;i++)
            creation();
            break;
            case 2:
                traversing();
                break;
                case 3:
                    
                    addatbeg();
                    break;
                    case 4:
                         int i;
                         cout<<"enter Position"<<endl;
                         cin>>i;
                         int data;
                         cout<<"Enter Data"<<endl;
                         cin>>data;
                        addafter(data,i);
                        break;
                        case 5:
                             int m;
                             cout<<"Enter data to be deleted"<<endl;
                            cin>>m;
                            deletion(m);
                            break;
                        case 6:
                             exit(0);
      default:
                            cout<<"Sorry!Wrong Choice :(";
                            cout<<endl;
                           
    }}
    getch();
    return(0);
}
void creation()
{
    struct node *temp;
    temp=(node*)malloc(sizeof(struct node));
    int data;
    cout<<"Enter Data ";
    cin>>data;
    temp->info=data;
    cout<<endl;
    if(last==NULL)
    {
        last=temp;
        last->link=last;
    }
    else
    {
        temp->link=last->link;
        last->link=temp;
        last=temp;
    }
}
void traversing()
{
    struct node *q;
    q=last->link;
    while(q!=last)
    {
        cout<<"data is "<<q->info;
        cout<<endl;
        q=q->link;
    }
    cout<<last->info;
    cout<<endl;
}
void addatbeg()
{
        int Data,k;
    struct node *tmp,*q;
    tmp=(node*)malloc(sizeof(struct node));
    cout<<"Enter Data";
    cin>>Data;
    cout<<endl;
    tmp->info=Data;
    tmp->link=last->link;
    last->link=tmp;
}
void addafter(int data, int pos)
{
     struct node *q,*tmp;
     int i;
     q=last->link;
     for(i=0;i<pos-1;i++)
     {
                         q=q->link;
                         if(q==last->link)
                         {
                                          cout<<"Less Elements "<<endl;
                                          return;
                         }
     }
                        
     tmp=(node*)malloc(sizeof(struct node));
     tmp->info=data;
     tmp->link=q->link;
     q->link=tmp;
     if(q==last)
     {
                last=tmp;
     }
}
void deletion(int data)
{
//    int chh,m,data;
        struct node *tmp,*q;
       
    if(last->link==last&&last->info==data)
            {
            tmp=last;
            last=NULL;
            free(tmp);
            return;
       
            }
           
                    q=last->link;
                    if(q->info==data)
                    {
                        tmp=q;
                        last->link=q->link;
                        free(tmp);
                        return;
                    }
                    while(q->link!=last)
                            {
                                if(q->link->info==data)
                                {
                                    tmp=q->link;
                                    q->link=tmp->link;
                                free(tmp);
                                return;
                            }
                                q=q->link;
   
                        }
                if(q->link->info==data)
                {
                    tmp=q->link;
                    q->link=last->link;
                    free(tmp);
                    last=q;
                    return;
                }
}