Insertion, Deletion ,Searching at First ,Last , At Given Position in Linked List Implementation in C++

#include<bits/stdc++.h>
using namespace std;
struct node
{
node *link;
int data;
}*start=NULL;
// INSERTION INTO LINKED LIST
void insertNode(int data)
{
node *temp=new node;
temp->link=NULL;
temp->data=data;
if(start==NULL)
{
start=temp;
return;
}
else
{
node *ptr=start;
while(ptr->link!=NULL)
{
ptr=ptr->link;
}
ptr->link=temp;
}
}
void insertInBetween(int data,int search)
{
node *temp=new node;
temp->data=data;
temp->link=NULL;
node *ptr=start;
while(ptr->link!=NULL and ptr->data!=search)
ptr=ptr->link;
temp->link=ptr->link;
ptr->link=temp;
}
void insertFirst(int data)
{
node *temp=new node;
temp->data=data;
temp->link=start;
start=temp;
}
void insertInBetweenBefore(int data,int search)
{
node *prev=NULL,*ptr=start,*temp=new node;
temp->data=data;
while(ptr->link!=NULL and ptr->data!=search)
{
prev=ptr;
ptr=ptr->link;
}
temp->link=prev->link;
prev->link=temp;
}

// ?? VARIOUS LINKED LIST DELETION OPERATIONS ?? //
void deleteFirst()
{
node *ptr=start;
if(ptr->link==NULL)
start=NULL;
else
start=ptr->link;

delete(ptr);
}
void deleteAtPosition(int pos)
{
node *ptr=start;
node *prev=NULL;
int count=0;
while(ptr->link!=NULL and count!=pos)
{
prev=ptr;
count+=1;
ptr=ptr->link;
}
prev->link=ptr->link;
delete(ptr);
}

void deleteLast()
{
node *ptr=start,*prev=NULL;
while(ptr->link!=NULL)
{
prev=ptr;
ptr=ptr->link;
}
prev->link=NULL;
delete(ptr);
}

void disp()
{
node *ptr=start;
while(ptr!=NULL)
{
cout<<" -->"<<ptr->data;
ptr=ptr->link;
}
}

int main()
{
insertNode(10);
insertNode(20);
insertNode(30);
insertNode(40);
cout<<"BEFORE\n";
disp();
cout<<"\nINSERTION AFTER 30\n";
insertInBetween(35,30);
disp();
cout<<"\nINSERTION AT FIRST NODE\n";
insertFirst(5);
disp();
cout<<"\nINSERTION BEFORE 30\n";
insertInBetweenBefore(25,30);
disp();
cout<<"\nDELETING FIRST ELEMENT\n";
deleteFirst();
disp();
cout<<"\nDELETING AT GIVEN POSITION =3:\n";
deleteAtPosition(3);
disp();
cout<<"\nDELETING LAST ELEMENT:\n";
deleteLast();
disp();


}

Pizza Hut Management System Project in C++

//This Program Is Created By Mohd Mujtaba Section-K1613 Roll No-B47 Reg No-11608125

//*******************************PROGRAM STARTS FROM HERE*********************************************
#include<iostream> // can be remove when using fstream
#include<fstream>
#include<conio.h> // getch()
#include<stdio.h> // gets,puts, 
#include<stdlib.h> // system("cls") system("PAUSE") exit() remove() rename()
#include<string.h> // strcpy strlen strcmp etc..
#include<iomanip>
#include<windows.h>   //Sleep()
#include<bits/stdc++.h>

using namespace std;

HANDLE console = GetStdHandle(STD_OUTPUT_HANDLE); // used for goto
COORD CursorPosition; 

void gotoxy(int x,int y)
{
CursorPosition.X=x;
CursorPosition.Y=y;
SetConsoleCursorPosition(console,CursorPosition); 

}

using namespace std;
fstream f1;
fstream f2;
fstream f3;
fstream f4;


int i,temp,found=0,total=0;
char chop='y';
int i_code1;



class menu
{
protected:
float price;
char p_name[20];
public:
int i_code;
void get_menu();
void show_menu();
void delPizzaMenu();
};
class order: public menu
{
protected:
char name[30],add[80];
int bill_no,i_code2;
long long mbno;
public:
void modify();

void get_order();
void show_order();
void gen_bill(int,int);
void search();
void del_rec();

};

class lovely_pizza:public order
{
public:




void home_page()
{

int menuch=1;
bool value=true;
int x=7;
// MENU:



while(value)
{
system("cls");
gotoxy(14,x);
cout<<"->";
system("color 1A");
gotoxy(18,1);
cout<<setw(30)<<"             ==================================================";
gotoxy(18,2);
// Sleep(150);
cout<<setw(30)<<"                      WELCOME TO LOVELY PIZZA PVT. LTD. ";
gotoxy(18,4);
// Sleep(150);
cout<<setw(30)<<"                               PHAGWARA PUNJAB";
gotoxy(18,5);
// Sleep(150);
cout<<setw(30)<<"            ===================================================";
gotoxy(18,6);
// Sleep(100);
gotoxy(18,7);
cout<<"1. NEW ORDER:";
gotoxy(18,8);
cout<<"2. ALL ORDER DETAILS:";
gotoxy(18,9);
cout<<"3. SEARCH ORDER";
gotoxy(18,10);
cout<<"4. Modify ORDER:";
gotoxy(18,11);
cout<<"5. Delete ORDER :";
gotoxy(18,12);
cout<<"6. Enter Pizza Menu Details:";
gotoxy(18,13);
cout<<"7. Show Pizza  MENU:";
gotoxy(18,14);
cout<<"8. Delete Pizza Details:";
gotoxy(18,15);
cout<<"9. Exit (Sign Out):";
gotoxy(18,16);
cout<<"Choose One Option...... :";
system("pause>nul"); // the >nul bit causes it the print no message

if(GetAsyncKeyState(VK_DOWN) && x != 16)
{
gotoxy(14,x);
cout<<"  ";
x++;
cout<<"->";
menuch++;
continue;
}
if(GetAsyncKeyState(VK_UP)&&x!=7)
{
gotoxy(14,x);
cout<<"  ";
x--;
cout<<"->";
menuch--;
continue;
}
if(GetAsyncKeyState(VK_RETURN))
{

switch(menuch)
{
case 1:
system("cls");

get_order();
// goto MENU; // REDIRECTED TO MENU LABEL
break;
case 2:
system("cls");
f2.open("D:/order.txt",ios::in|ios::out|ios::app);
show_order();
// goto MENU; // REDIRECTED TO MENU LABEL
break;
case 3:
search();
cout<<"Press Again Any Key...#BACK #TO #MENU:";
getch();
// goto MENU; // REDIRECTED TO MENU LABEL
break;
case 4:
system("cls");
modify();
// goto MENU; // REDIRECTED TO MENU LABEL
break;
    case 5:
    del_rec();
// goto MENU; // REDIRECTED TO MENU LABEL
break;
     
case 6:

        f1.open("D:\\menu.txt",ios::out|ios::app);
    get_menu();
f1.close();
// goto MENU; // REDIRECTED TO MENU LABEL
break;
case 7:
system("cls");
    f1.open("D:/menu.txt");
    show_menu();
    f1.close();
    getch();
    // goto MENU; // REDIRECTED TO MENU LABEL
    break;
case 8:
delPizzaMenu();
// goto MENU; // REDIRECTED TO MENU LABEL
break;
case 9:
system("cls");

for(i=0;i<50;i++)
{

cout<<"/";
if(i==26)
cout<<"Saving And Exiting.....:";
Sleep(30);
}

exit(42);
value=false;

}
}
}
gotoxy(18,19);
}

}pizza;

void menu::get_menu()
{
system("color 2F");
do
{
system("cls");
cout<<setw(30)<<"Enter All Pizza DETAILS With PRICES:\n\n";
cout<<"Enter Item Code:";
fflush(stdin);
    
cin>>i_code;
cout<<"Pizza Name;";
fflush(stdin);
gets(p_name);
cout<<"Price:";
cin>>price;
f1.write((char*)&pizza,sizeof(pizza));
system("cls");
cout<<"Record Entered.......\n"<<setw(15)<<"Want To Enter Any More (Y/N):";
cin>>chop;

}while(chop=='y'||chop=='Y');
}

void menu::show_menu()
{
system("color 1A");
cout<<"Item_Code"<<setw(18)<<"Name"<<setw(25)<<"Price"<<"\n";
while(f1.read((char*)&pizza,sizeof(pizza)))
cout<<i_code<<setw(25)<<p_name<<setw(20)<<price<<"\n";
}

void order::modify()
{
MODIFY:
found=0;
int mbno1,x;
char cnfModify;
cout<<"Enter Mobile_No:";
cin>>mbno1;
f2.open("D:\\order.txt",ios::in|ios::out|ios::app);
f3.open("D:\\order1.txt",ios::in|ios::out|ios::app);


cout<<"Bill_No:"<<setw(10)<<"Name"<<setw(20)<<"Address"<<setw(20)<<"Mobile No"<<setw(20)<<"Pizza Code"<<"\n";
while(f2.read((char*)&pizza,sizeof(pizza)))
{
if(mbno1==mbno)
{
cout<<bill_no<<setw(20)<<name<<setw(20)<<add<<setw(15)<<mbno<<setw(20)<<i_code2<<"\n";
//
//
cout<<"\nWant To Modify This:(Y/y):";
fflush(stdin);
cin>>cnfModify;
fflush(stdin);
if(cnfModify=='y'||cnfModify=='Y')
{
cout<<"\nEnter New Pizza Code:";
cin>>i_code2;

}
f3.write((char*)&pizza,sizeof(pizza));
found=1;
}


}
if(found==0)
{
cout<<"File Not Found!!! ENTER AGAIN::";
system("PAUSE");
f2.close();
    f3.close();
goto MODIFY;
}

f2.close();
f3.close();



f2.open("D:\\order.txt",ios::in|ios::out|ios::app);
f3.open("D:\\order1.txt",ios::in|ios::out|ios::app);
while(f2.read((char*)&pizza,sizeof(pizza)))
{
if(mbno1==mbno)
continue;
else
f3.write((char*)&pizza,sizeof(pizza));
}
f2.close();
f3.close();
remove("D://order.txt");
rename("D://order1.txt","D://order.txt");

cout<<"\n\n Record Updated!! Press Any Key For MENU";
getch();
}

void order::get_order()
{
    int x,tempBillCount=0;
char ch;
f2.open("D:\\order.txt",ios::out|ios::in|ios::app);
while(f2.read((char*)&pizza,sizeof(pizza)))
{
tempBillCount++;

}
f2.close();
f2.open("D:\\order.txt",ios::out|ios::in|ios::app);
bill_no=tempBillCount+1;
cout<<"Enter Name:";
fflush(stdin);
gets(name);
cout<<"Enter Address:";
fflush(stdin);
gets(add);
cout<<"Enter Mobile Number:";
cin>>mbno;
fflush(stdin);

AGAIN:                   //GOTO STATEMENT

cout<<"Enter Pizza(ITEM) Code:";
fflush(stdin);
cin>>i_code2;  

f2.write((char*)&pizza,sizeof(pizza));    //storing The Data of Only Pizza Menu And That is also of last menu
  cout<<"Do You Want To Enter More:";
cin>>ch;
if(ch=='y'||ch=='Y')
goto AGAIN; // goto to again LABEL
f2.close();
gen_bill(mbno,bill_no);
getch();                 //its just like printing the bill after order;

       
}
void order::show_order()
{
system("Color 5F");
int x;
// f1.open("D:\\menu.txt",ios::in|ios::out|ios::app);
cout<<"Bill_No:"<<setw(10)<<"Name"<<setw(20)<<"Address"<<setw(20)<<"Mobile No"<<setw(20)<<"Pizza Code"<<"\n\n";
while(f2.read((char*)&pizza,sizeof(pizza)))
{
cout<<bill_no<<setw(20)<<name<<setw(20)<<add<<setw(15)<<mbno<<setw(20)<<i_code2<<"\n";
x=i_code2;
fflush(stdin);
//cout<<"\nItem_Code"<<setw(18)<<"Pizza Name"<<setw(25)<<"Price"<<"\n\n";
// cout<<i_code2<<setw(25)<<p_name<<setw(20)<<price<<"\n";


}
getch();

f2.close();

/* while(f1.read((char*)&pizza,sizeof(pizza)));
{
if(x==i_code)
{

cout<<"\nItem_Code"<<setw(18)<<"Pizza Name"<<setw(25)<<"Price"<<"\n\n";
cout<<i_code<<setw(25)<<p_name<<setw(20)<<price<<"\n";
cout<<"\n\n\n\n\n\n\n"<<setw(50)<<"Amount-->RS "<<total;
}
f1.close();


} */

}

void order::gen_bill(int a, int tempBillNo)
{
system("color 1A");
int i_bill;
float total=0;

system("cls");
cout<<setw(80)<<"_______________________________________\n";
cout<<setw(80)<<"|=====================================|\n";
cout<<setw(80)<<"|          LOVELY PIZZA PVT. LTD      |\n";
cout<<setw(80)<<"|                                     |\n";
cout<<setw(80)<<"|       Jalandhar-Phagwara Highway    |\n";
cout<<setw(80)<<"|             Chehru -Punjab          |\n";
cout<<setw(82)<<"|=====================================|\n\n\n";

cout<<"Customer Name:"<<name<<"\t\tBill No:"<<tempBillNo;
cout<<"\nAddress:"<<add;
cout<<"\nContact No:"<<mbno;
//f1.open("D:\\menu.txt",ios::in|ios::out|ios::app);
f2.open("D:\\order.txt",ios::in|ios::out|ios::app);
cout<<"\n===================================================================\n";
cout<<"\n===================================================================\n";
cout<<"\n\nItem_Code"<<setw(18)<<"Pizza Name"<<setw(25)<<"Price"<<"\n\n";
while(f2.read((char*)&pizza,sizeof(pizza)))
{
if(a==mbno)
{
i_bill=i_code2;

f1.open("D:\\menu.txt",ios::in|ios::out|ios::app);
while(f1.read((char*)&pizza,sizeof(pizza)))
{
if(i_bill==i_code)
{
cout<<i_code<<setw(25)<<p_name<<setw(20)<<price<<"\n";
total+=price;
break;
}

}
f1.close();
}
    }
    cout<<"\n\n"<<setw(40)<<"TOTAL COST FOR ORDER IS RS:"<<total<<"\n";
    cout<<setw(50)<<"THANK YOU! AND VISIT AGAIN:\n";
//f1.close();
f2.close();
}

void order::search()
{
  system("Color 2F");
 
long b;
  float total=0;

  Back: //goto function to move back and search again.....

  system("cls");
  found=0;
cout<<"Enter Mobile_No To Be Searched: \n"<<setw(10)<<"Enter 99 Any time When You Wish To go Back(MENU): ";
cin>>b;
f2.open("D:\\order.txt",ios::in|ios::out|ios::app);
while(f2.read((char*)&pizza,sizeof(pizza)))
{
if(b==mbno)
{
cout<<"\n\nCustomer Name:"<<name;
cout<<"\nAddress:"<<add;
cout<<"\nContact No:"<<mbno;
found=1;
break;
}
}
f2.close();
if(found==1)
{
cout<<"\n\nItem_Code"<<setw(18)<<"Pizza Name"<<setw(25)<<"Price"<<"\n\n";
f2.open("D:\\order.txt",ios::in|ios::out|ios::app);
// f2.seekp(0,ios::beg);
while(f2.read((char*)&pizza,sizeof(pizza)))
{
if(b==mbno)
{
temp=i_code2;

f1.open("D:\\menu.txt",ios::in|ios::out|ios::app);
while(f1.read((char*)&pizza,sizeof(pizza)))
{
if(temp==i_code)
{
cout<<i_code<<setw(25)<<p_name<<setw(20)<<price<<"\n";
total+=price;
break;
}

}
f1.close();
}
}
cout<<"\n\n"<<setw(20)<<"TOTAL COST FOR PIZZA IZZ RS:"<<total<<"\n";
}


if (found==0)
{
    if(b==99)
    goto MENU;
system("cls");
cout<<"File/Record Not Found!!\n Press any key to enter again.....";
getch();
goto Back;
}

MENU:
f1.close();
f2.close();
}


void order::del_rec()
{
system("color 7C");
searchAgain:             //GOTO STATEMENT 
found=0;
long long x;
char ch;

cout<<"Enter Mobile Number:"<<setw(10)<<"(ENTER 99 ANY TIME #TO #GO #BACK::)";
cin>>x;
f2.open("D://order.txt",ios::in|ios::out|ios::app);
while(f2.read((char*)&pizza,sizeof(pizza)))
{
if(x==mbno)
{
cout<<"\n\nCustomer Name:"<<name;
cout<<"\nAddress:"<<add;
cout<<"\nContact No:"<<mbno;
temp=i_code2;
found=1;
}
}
f2.close();
if (found==0)
{
    if(x==99)
    goto MENU;
system("cls");
cout<<"File/Record Not Found!!\n Press any key to enter again.....";
getch();
goto searchAgain;
}

if(found==1)
cout<<"\n\nItem_Code"<<setw(18)<<"Pizza Name"<<setw(25)<<"Price"<<"\n\n";
f1.open("D:\\menu.txt",ios::in|ios::out|ios::app);

while(f1.read((char*)&pizza,sizeof(pizza)))
{
if(temp==i_code)
{
cout<<i_code<<setw(25)<<p_name<<setw(20)<<price<<"\n";

}


}
     // MENU LOCAL GOTO Object;

f1.close();
MENU:  

f2.open("D://order.txt",ios::in);
f3.open("D://order1.txt",ios::in|ios::out|ios::app);
while(f2.read((char*)&pizza,sizeof(pizza)))
{
if(x==mbno)
continue;
f3.write((char*)&pizza,sizeof(pizza));
}
f2.close();
f3.close();
remove("D://order.txt");
rename("D://order1.txt","D://order.txt");






}

void menu::delPizzaMenu()
{
system("color 5F");
int tempIcode;
found=0;
f1.open("D://menu.txt",ios::in|ios::out|ios::app);
delPizzaMenu:
cout<<"Enter Pizza Code:";
cin>>tempIcode;
while(f1.read((char*)&pizza,sizeof(pizza)))
{
if(tempIcode==i_code)
{
cout<<i_code<<setw(25)<<p_name<<setw(20)<<price<<"\n";
found=1;
}
}
f1.close();
if(found!=1)
{
if(tempIcode==99)
goto delPizzaMenu1;
cout<<"Required Data Is Not Found!!!,\n   PRESS ANY KEY TO ENTER AGAIN(ENTER 99 To GO BACK):\n";
getch();
goto delPizzaMenu;
}


f1.open("D://menu.txt",ios::in);
f4.open("D://menu1.txt",ios::in|ios::out|ios::app);
delPizzaMenu1: // goto function
while(f1.read((char*)&pizza,sizeof(pizza)))
{
if(tempIcode==i_code)
continue;
f4.write((char*)&pizza,sizeof(pizza));
}
f1.close();
f4.close();
remove("D://menu.txt");
rename("D://menu1.txt","D://menu.txt");


}




main()
{
system("Color 6B");
char pass[256] = {0},c;
    char pass1[] = "mujtaba1@";
    int pos = 0,count=0;
    Sleep(300);
    cout<<setw(30)<<"               ============================================\n";
    Sleep(300);
    cout<<setw(45)<<"                           PIZZA MANAGEMENT SYSTEM\n";
    Sleep(300);
    cout<<setw(45)<<"                         CREATED BY- MOHAMMAD MUJTABA\n";
    Sleep(300);
    cout<<setw(45)<<"                               SECTION - K1613\n";
    Sleep(300);
    cout<<setw(45)<<"                                ROLL NO- B47\n";
    Sleep(300);
    cout<<setw(30)<<"               =============================================\n";
    Sleep(300);
    cout<<setw(30)<<"               =============================================\n";
    Sleep(300);
    cout<<setw(30)<<"                          LOGIN INTERFACE (AUTHORIZED)\n";
    Sleep(300);
    cout<<setw(30)<<"               =============================================\n\n";
    Sleep(300);
    login:  // GOTO FUNCTION
    
    cout<<"\nEnter Password (Max 3 attempts) : ";
    
    do {
        c = getch();

        if( isprint(c) ) 
        {
            pass[ pos++ ] = c;
            cout<<'*';
        }
        else if( c == 8 && pos )
        {
            pass[ pos-- ] = '\0';
            cout<<"\b\b";
            
        }
    } while( c != 13 );
    
    system("cls");
    cout<<"Please Wait System Is Verifing data";
    for(i=0;i<40;i++)
    {
    Sleep(59);
    cout<<"_";
}

    if( !strcmp(pass,pass1) )
        {
        system("cls");
        cout<<setw(40)<<"                  PLEASE WAIT WHILE PROGRAM IS LOADING>>\n";
            for(i=0;i<40;i++)
     {
cout<<"/\\";
Sleep(50);

            }
        }
    else
        {
  cout<<"\n Wrong Password!!!\n PRESS ANY KEY & TRY AGAIN";
  getch();
  count++;
  if(count==3)
  exit(42);
  else 
  goto login;
 }
pizza.home_page();
}

Pre Order Traversal In Binary Tree | Recursive Method | C++, C Program

//Watch Video @ youtube https://youtu.be/ZFAWcg3yVuo
#include<bits/stdc++.h>
using namespace std;

struct node
{
node *left;
node *right;
int data;
};

node *insertNode(node *root,int info)
{
if(root==NULL)
{
root=new node;
root->left=NULL;
root->right=NULL;
root->data=info;
return(root);
}
else
{
if(root->data<info)
root->right=insertNode(root->right,info);
else
root->left=insertNode(root->left,info);
}
return(root);
}
/*
void inOrder(node *root)
{
if(root!=NULL)
{
inOrder(root->left);
cout<<" "<<root->data;
inOrder(root->right);
}
}
*/
void preOrder(node *root)
{
if(root!=NULL)
{
cout<<" "<<root->data;
preOrder(root->left);
preOrder(root->right);
}
}
/*
void postOrder(node *root)
{
if(root!=NULL)
{
postOrder(root->left);
postOrder(root->right);
cout<<" "<<root->data;
}
}

*/


main()
{
node *root=NULL;
root=insertNode(root,10);
root=insertNode(root,30);
root=insertNode(root,20);
root=insertNode(root,70);
root=insertNode(root,40);
root=insertNode(root,60);
root=insertNode(root,50);
cout<<"INORDER\n";
inOrder(root);
cout<<"\nPOSTORDER\n";
postOrder(root);
cout<<"\nPREORDER\n";
preOrder(root);

}

Implement Queue using Stacks (Geek4Geeks Code) in C++

Implement Queue using Stacks (Geek4Geeks Code) in C++

   /* Program to implement a queue using two stacks */
#include
#include
/* structure of a stack node */
struct sNode
{
    int data;
    struct sNode *next;
};
/* Function to push an item to stack*/
void push(struct sNode** top_ref, int new_data);
/* Function to pop an item from stack*/
int pop(struct sNode** top_ref);
/* structure of queue having two stacks */
struct queue
{
    struct sNode *stack1;
    struct sNode *stack2;
};
/* Function to enqueue an item to queue */
void enQueue(struct queue *q, int x)
{
    push(&q->stack1, x);
}
/* Function to dequeue an item from queue */
int deQueue(struct queue *q)
{
    int x;
    /* If both stacks are empty then error */
    if(q->stack1 == NULL && q->stack2 == NULL)
    {
        printf("Q is empty");
        getchar();
        exit(0);
    }
/* Move elements from satck1 to stack 2 only if
stack2 is empty */
if(q->stack2 == NULL)
{
    while(q->stack1 != NULL)
    {
        x = pop(&q->stack1);
        push(&q->stack2, x);
         
    }
}
x = pop(&q->stack2);
return x;
}
/* Function to push an item to stack*/
void push(struct sNode** top_ref, int new_data)
{
    /* allocate node */
    struct sNode* new_node =
        (struct sNode*) malloc(sizeof(struct sNode));
        if(new_node == NULL)
        {
            printf("Stack overflow \n");
            getchar();
            exit(0);
             
        }
/* put in the data */
new_node->data = new_data;
/* link the old list off the new node */
new_node->next = (*top_ref);
/* move the head to point to the new node */
(*top_ref) = new_node;
}
/* Function to pop an item from stack*/
int pop(struct sNode** top_ref)
{
    int res;
    struct sNode *top;
     
    /*If stack is empty then error */
    if(*top_ref == NULL)
    {
        printf("Stack overflow \n");
        getchar();
        exit(0);
         
    }
    else
    {
        top = *top_ref;
        res = top->data;
        *top_ref = top->next;
        free(top);
        return res;
         
    }
}
/* Driver function to test anove functions */
int main()
{
    /* Create a queue with items 1 2 3*/
    struct queue *q = (struct queue*)malloc(sizeof(struct queue));
    q->stack1 = NULL;
    q->stack2 = NULL;
    enQueue(q, 1);
    enQueue(q, 2);
    enQueue(q, 3);
     
    /* Dequeue items */
    printf("%d ", deQueue(q));
    printf("%d ", deQueue(q));
    printf("%d ", deQueue(q));
getchar();
}

Circular Linked List Implementation Data Structure in C/ C++

#include<bits/stdc++.h>
#include<conio.h>
using namespace std;
struct node
{
int info;
node *link;
};
void insert(struct node **start,int num)
{
cout<<"First";

node *temp=new node;
temp->info=num;

temp->link=NULL;

(*start)=temp;

}
void insertEnd(node *start,int num)
{
cout<<"\nLast:";
node *temp;
while(start->link!=NULL)
{
start=start->link;
}
temp=new node;
temp->info=num;
temp->link=NULL;
start->link=temp;

}

void makeCircular(node *start)
{
node *temp=start;
while(start->link!=NULL)
{

    start=start->link;
}
if(start->link==NULL)
{
start->link=temp;
}
}
void disp1(node *start)
{
node *temp=start;
while(temp->link!=start)
{
cout<<" "<<temp->info;
    temp=temp->link;
}
cout<<" "<<temp->info;
}


main()
{
struct node *start=NULL;

int num,x,y;
cout<<"In Main";
insert(&start,1);
insertEnd(start,5);
insertEnd(start,3);
insertEnd(start,4);
insertEnd(start,6);
insertEnd(start,7);
insertEnd(start,8);
insertEnd(start,9);
insertEnd(start,10);

makeCircular(start);
disp1(start);

}

Alternate Node Deletion in Singly Linked List in C/C++ Implementation

#include<iostream>
using namespace std;

struct node
{
int info;
node *link;
};

void insertFirst(node **start,int num)
{
node *temp=new node;
temp->info=num;
temp->link=NULL;
*start=temp;
cout<<"First:\n";
}

void insertLast(node *start,int num)
{
node *temp=new node;
temp->info=num;
temp->link=NULL;
while(start->link!=NULL)
{
start=start->link;
}
start->link=temp;
}

void deleteAlternate(node *start)
{
node *currnext=start->link;
node *nexttonext=start->link->link;
node *curr=start;
while(curr!=NULL &&curr->link!=NULL && curr->link->link!=NULL)
{
nexttonext=curr->link->link;
delete(curr->link);
curr->link=nexttonext;
curr=curr->link;
}
}




void disp(node *start)
{
while(start!=NULL)
{
cout<<" "<<start->info;
start=start->link;
}
cout<<"\n";
}





main()
{
node *start=NULL;
insertFirst(&start,1);
insertLast(start,2);
insertLast(start,3);
insertLast(start,4);
insertLast(start,5);
        cout<<"Before Deleting Linked List\n:";
disp(start);
deleteAlternate(start);
        cout<<"After Deleting Alternate Node:\n";
disp(start);
}

Insertion into Linked List after an element specified by user in C++/C

#include<iostream>
using namespace std;

struct node
{
int info;
node *link;
};

void insertFirst(node **start,int num)
{
node *temp=new node;
temp->info=num;
temp->link=NULL;
*start=temp;
cout<<"First:\n";
}

void insertLast(node *start,int num)
{
node *temp=new node;
temp->info=num;
temp->link=NULL;
while(start->link!=NULL)
{
start=start->link;
}
start->link=temp;
}

void insertAtPos(node *start,int num,int num1)
{
node *temp=new node;
temp->info=num1;
temp->link=NULL;
node *prev=start;
while(start!=NULL)
{
if(start->info==num)
break;
else
prev=start;
start=start->link;
}
temp->link=start->link;
start->link=temp;

}

void disp(node *start)
{
while(start!=NULL)
{
cout<<" "<<start->info;
start=start->link;
}
}




main()
{
node *start=NULL;
insertFirst(&start,1);
insertLast(start,2);
insertLast(start,3);
insertLast(start,4);
insertLast(start,5);
insertAtPos(start,2,6);
disp(start);
}

Header Linked List - Implementation in C++/C

#include<bits/stdc++.h>

using namespace std;

struct node
{
int info;
node *link;
};
struct header
{
node *next;
int total=0;
};

void insertFirst(node **start,int data,header *head)
{
node *temp=new node;
temp->info=data;
temp->link=NULL;
*start=temp;
head->next=temp;
head->total+=1;
}
void insertLast(node *start,header *head,int data)
{
node *temp=new node;

while(start->link!=NULL)
{
start=start->link;
}
start->link=temp;
temp->link=NULL;
temp->info=data;
head->total+=1;
}

void display(node *start,header *head)
{
cout<<"Elements are:\n";
while(start!=NULL)
{
cout<<" "<<start->info;
start=start->link;
}
cout<<"\nTotal Number Of Elements Are:"<<head->total;
}

void deleteAlternate(node *start,header *head)
{
cout<<"\nIn Delete Function:\n";
node *nexttonext;
node *curr=start;
while(curr!=NULL&&curr->link!=NULL)
{


if(curr->link->info%2!=0)
{
nexttonext=curr->link->link;
delete(curr->link);
curr->link=nexttonext;
head->total-=1;
curr=curr->link;
}


}


}
main()
{
int i=0;
char ch='y';
node *start=NULL;
header *head =new header;
cout<<"First Element Entered:\n";
while(ch=='y'||ch=='Y')
{

if(i==0)
insertFirst(&start,i,head),i++;
else
insertLast(start,head,i),i++;

cout<<"Do You Want More Record:";
cin>>ch;
}
display(start,head);
deleteAlternate(start,head);
display(start,head);
}