#include 
typedef struct node
{
    int data;
    struct node *link;
}NODE;

void Insert(int);
int  Delete();
void Display();
NODE *front,*rear;   /* Global Declarations */

main()
{
    /* Main Program */
    int opn,elem;
    front=rear=NULL;
    do
    {
        clrscr();
        printf("\n ### Linked List Implementation of QUEUE Operations ### \n\n");
        printf("\n Press 1-Insert, 2-Delete, 3-Display,4-Exit\n");
        printf("\n Your option ? ");
        scanf("%d",&opn);
        switch(opn)
        {
        case 1:
            printf("\n\nRead the Element to be Inserted ?");
            scanf("%d",&elem);
            Insert(elem);
            break;
        case 2:
            elem=Delete();
            if(elem != -1)
                printf(" Deleted Node(From Front)with the Data: %d\n",elem);
            break;
        case 3: printf("Linked List Implementation of Queue: Status:\n");
            Display(); break;
        case 4: printf("\n\n Terminating \n\n"); break;
        default: printf("\n\nInvalid Option !!! Try Again !! \n\n");
            break;
        }
        printf("\n\n\n\n  Press a Key to Continue . . . ");
        getch();
    }while(opn != 4);
}

void Insert(int info)
{
    NODE *temp;
    temp=(NODE *)malloc(sizeof(NODE));
    if( temp == NULL)
        printf(" Out of Memory !! Overflow !!!");
    else
    {
        temp->data=info;
        temp->link=NULL;
        if(front == NULL) { front = rear = temp; } /* First Node? */
        else
        { rear->link=temp; rear = temp; }       /* Insert End */
        printf(" Node has been inserted at End Successfully !!");
    }
}

int Delete()
{
    int info;
    NODE *t;
    if( front ==  NULL) { printf(" Underflow!!!"); return -1; }
    else
    {
        t=front;
        info=front->data;
        if(front == rear) rear=NULL;
        front=front->link;
        t->link=NULL;
        free(t);
        return(info);
    }
}

void Display()
{
    NODE *t;
    if( front == NULL) printf("Empty Queue\n");
    else
    {
        t=front;
        printf("Front->");
        while(t)
        {
            printf("[%d]->",t->data);
            t=t->link;
        }
        printf("Rear\n");
    }
}

The post C Program to implement QUEUE operations using Linked Lists first appeared on Student Projects.

#define SIZE 5            /* Size of Queue */
int Q[SIZE],f=0,r=-1;       /* Global declarations */

Qinsert(int elem)
{                       /* Function for Insert operation */
    if( Qfull()) printf("\n\n Overflow!!!!\n\n");
    else
    {
        ++r;
        Q[r]=elem;
    }
}

int Qdelete()
{                      /* Function for Delete operation */
    int elem;
    if(Qempty()){ printf("\n\nUnderflow!!!!\n\n");
    return(-1); }
    else
    {
        elem=Q[f];
        f=f+1;
        return(elem);
    }
}

int Qfull()
{                     /* Function to Check Queue Full */
    if(r==SIZE-1) return 1;
    return 0;
}

int Qempty()
{                    /* Function to Check Queue Empty */
    if(f > r) return 1;
    return 0;
}

display()
{                  /* Function to display status of Queue */
    int i;
    if(Qempty()) printf(" \n Empty Queue\n");
    else
    {
        printf("Front->");
        for(i=f;i<=r;i++)
            printf("%d ",Q[i]);
        printf("<-Rear");
    }
}

main()
{                         /* Main Program */
    int opn,elem;
    do
    {
        clrscr();
        printf("\n ### Queue Operations ### \n\n");
        printf("\n Press 1-Insert, 2-Delete,3-Display,4-Exit\n");
        printf("\n Your option ? ");
        scanf("%d",&opn);
        switch(opn)
        {
        case 1: printf("\n\nRead the element to be Inserted ?");
            scanf("%d",&elem);
            Qinsert(elem); break;
        case 2: elem=Qdelete();
            if( elem != -1)
                printf("\n\nDeleted Element is %d \n",elem);
            break;
        case 3: printf("\n\nStatus of Queue\n\n");
            display(); break;
        case 4: printf("\n\n Terminating \n\n"); break;
        default: printf("\n\nInvalid Option !!! Try Again !! \n\n");
            break;
        }
        printf("\n\n\n\n  Press a Key to Continue . . . ");
        getch();
    }while(opn != 4);
}

The post C Program for Simple/Linear QUEUE Operations – Using Array first appeared on Student Projects.

#include
#include
#define max 5
int q[10],front=0,rear=-1;
void main()
{
    int ch;
    void insert();
    void delet();
    void display();
    clrscr();
    printf("\nQueue operations\n");
    printf("1.insert\n2.delete\n3.display\n4.exit\n");
    while(1)
    {
        printf("Enter your choice:");
        scanf("%d",&ch);
        switch(ch)
        {
        case 1: insert();
            break;
        case 2: delet();
            break;
        case 3:display();
            break;
        case 4:exit();
        default:printf("Invalid option\n");
        }
    }
}

void insert()
{
    int x;
    if(rear==max-1)
        printf("Queue is overflow\n");
    else
    {
        printf("Enter element to be insert:");
        scanf("%d",&x);
        q[++rear]=x;
    }
}
void  delet()
{
    int a;
    if((front==0)&&(rear==-1))
    {
        printf("Queue is underflow\n");
        getch();
        exit();
    }
    a=q[front++];
    printf("Deleted element is:%d\n",a);
    if(front>rear)
    {
        front=0;
        rear=-1;
    }
}

void display()
{
    int i;
    if(front==0&&rear==-1)
    {
        printf("Queue is underflow\n");
        getch();
        exit();
    }
    for(i=front;i<=rear;i++)
        printf("\t%d",q[i]);
    printf("\n");
}
getch();

The post C program to implement queue operations first appeared on Student Projects.