Create DEQueue-using-array.c

DEQueue-using-array.c

@@ -0,0 +1,184 @@
+#include<stdio.h>
+#include<stdlib.h>
+#define MAX 7
+
+int deque_arr[MAX];
+int front=-1;
+int rear=-1;
+
+void insert_frontEnd(int item);
+void insert_rearEnd(int item);
+int delete_frontEnd();
+int delete_rearEnd();
+void display();
+int isEmpty();
+int isFull();
+
+int main()
+{
+        int choice,item;
+        while(1)
+        {
+                printf("\n\n1.Insert at the front end\n");
+                printf("2.Insert at the rear end\n");
+                printf("3.Delete from front end\n");
+                printf("4.Delete from rear end\n");
+                printf("5.Display\n");
+                printf("6.Quit\n");
+                printf("\nEnter your choice : ");
+                scanf("%d",&choice);
+
+                switch(choice)
+                {
+                case 1:
+                        printf("\nInput the element for adding in queue : ");
+                        scanf("%d",&item);
+                        insert_frontEnd(item);
+                        break;
+                case 2:
+                        printf("\nInput the element for adding in queue : ");
+                        scanf("%d",&item);
+                        insert_rearEnd(item);
+                        break;
+                 case 3:
+                        printf("\nElement deleted from front end is : %d\n",delete_frontEnd());
+                        break;
+                 case 4:
+                        printf("\nElement deleted from rear end is : %d\n",delete_rearEnd());
+                        break;
+                 case 5:
+                        display();
+                        break;
+                 case 6:
+                        exit(1);
+                 default:
+                        printf("\nWrong choice\n");
+                }/*End of switch*/
+                printf("\nfront = %d, rear =%d\n", front , rear);
+                display();
+        }/*End of while*/
+}/*End of main()*/
+
+void insert_frontEnd(int item)
+{
+        if( isFull() )
+        {
+                printf("\nQueue Overflow\n");
+                return;
+        }
+        if( front==-1 )/*If queue is initially empty*/
+        {
+                front=0;
+                rear=0;
+        }
+        else if(front==0)
+                front=MAX-1;
+        else
+                front=front-1;
+        deque_arr[front]=item ;
+}/*End of insert_frontEnd()*/
+
+void insert_rearEnd(int item)
+{
+        if( isFull() )
+        {
+                printf("\nQueue Overflow\n");
+                return;
+        }
+        if(front==-1)  /*if queue is initially empty*/
+        {
+                front=0;
+                rear=0;
+        }
+        else if(rear==MAX-1)  /*rear is at last position of queue */
+                rear=0;
+        else
+                rear=rear+1;
+        deque_arr[rear]=item ;
+}/*End of insert_rearEnd()*/
+
+int delete_frontEnd()
+{
+        int item;
+        if( isEmpty() )
+        {
+                printf("\nQueue Underflow\n");
+                exit(1);
+        }
+        item=deque_arr[front];
+        if(front==rear) /*Queue has only one element */
+        {
+                front=-1;
+                rear=-1;
+        }
+        else
+                if(front==MAX-1)
+                        front=0;
+                else
+                        front=front+1;
+        return item;
+}/*End of delete_frontEnd()*/
+
+int delete_rearEnd()
+{
+        int item;
+        if( isEmpty() )
+        {
+                printf("\nQueue Underflow\n");
+                exit(1);
+        }
+        item=deque_arr[rear];
+
+        if(front==rear) /*queue has only one element*/
+        {
+                front=-1;
+                rear=-1;
+        }
+        else if(rear==0)
+                rear=MAX-1;
+        else
+                rear=rear-1;
+        return item;
+}/*End of delete_rearEnd() */
+
+int isFull()
+{
+        if ( (front==0 && rear==MAX-1) || (front==rear+1) )
+                return 1;
+        else
+                return 0;
+}/*End of isFull()*/
+
+int isEmpty()
+{
+        if( front == -1)
+                return 1;
+        else
+                return 0;
+}/*End of isEmpty()*/
+
+void display()
+{
+        int i;
+        if( isEmpty() )
+        {
+                printf("\nQueue is empty\n");
+                return;
+        }
+        printf("\nQueue elements :\n");
+        i=front;
+        if( front<=rear )
+        {
+                while(i<=rear)
+                        printf("%d ",deque_arr[i++]);
+        }
+        else
+        {
+                while(i<=MAX-1)
+                        printf("%d ",deque_arr[i++]);
+                i=0;
+                while(i<=rear)
+                        printf("%d ",deque_arr[i++]);
+        }
+        printf("\n");
+}/*End of display() */