Merge pull request #70 from SMARTA01/patch-1

Created Double Ended queue

DoublyEndedQ.c

@@ -0,0 +1,181 @@
+# include<stdio.h>
+# define MAX 5
+
+int deque_arr[MAX];
+int left = -1;
+int right = -1;
+
+
+void insert_right()
+{
+	int added_item;
+	if((left == 0 && right == MAX-1) || (left == right+1))
+	{	printf("Queue Overflow\n");
+		return;}
+	if (left == -1)  /* if queue is initially empty */
+	{	left = 0;
+		right = 0;}
+	else
+	if(right == MAX-1)  /*right is at last position of queue */
+		right = 0;
+	else
+		right = right+1;
+	printf("Input the element for adding in queue : ");
+	scanf("%d", &added_item);
+	deque_arr[right] = added_item ;
+}
+
+void insert_left()
+{	int added_item;
+	if((left == 0 && right == MAX-1) || (left == right+1))
+	{	printf("Queue Overflow \n");
+		return;	 }
+	if (left == -1)/*If queue is initially empty*/
+	{	left = 0;
+		right = 0;	 }
+	else
+	if(left== 0)
+		left=MAX-1;
+	else
+		left=left-1;
+	printf("Input the element for adding in queue : ");
+	scanf("%d", &added_item);
+	deque_arr[left] = added_item ;	 }
+
+void delete_left()
+{	if (left == -1)
+	{	printf("Queue Underflow\n");
+		return ;	}
+	printf("Element deleted from queue is : %d\n",deque_arr[left]);
+	if(left == right) /*Queue has only one element */
+	{	left = -1;
+		right=-1;	 }
+	else
+		if(left == MAX-1)
+			left = 0;
+		else
+			left = left+1;
+}
+
+void delete_right()
+{if (left == -1)
+	{printf("Queue Underflow\n");
+		return ;	 }
+	printf("Element deleted from queue is : %d\n",deque_arr[right]);
+	if(left == right) /*queue has only one element*/
+	{	left = -1;
+		right=-1;	 }
+	else
+		if(right == 0)
+			right=MAX-1;
+		else
+			right=right-1;	}
+
+void display_queue()
+{	int front_pos = left,rear_pos = right;
+	if(left == -1)
+	{	printf("Queue is empty\n");
+		return;	 }
+	printf("Queue elements :\n");
+	if( front_pos <= rear_pos )
+	{	while(front_pos <= rear_pos)
+		{	printf("%d ",deque_arr[front_pos]);
+			front_pos++;	}	}
+	else
+	{	while(front_pos <= MAX-1)
+		{	printf("%d ",deque_arr[front_pos]);
+			front_pos++;	}
+		front_pos = 0;
+		while(front_pos <= rear_pos)
+		{	printf("%d ",deque_arr[front_pos]);
+			front_pos++;
+		}
+	}
+	printf("\n");
+}
+
+void input_que()
+{	int choice;
+	do
+	{	printf("1.Insert at right\n");
+		printf("2.Delete from left\n");
+		printf("3.Delete from right\n");
+		printf("4.Display\n");
+		printf("5.Quit\n");
+		printf("Enter your choice : ");
+		scanf("%d",&choice);
+
+		switch(choice)
+		{	case 1:
+			insert_right();
+			break;
+		 case 2:
+			delete_left();
+			break;
+		 case 3:
+			delete_right();
+			break;
+		 case 4:
+			display_queue();
+			break;
+		 case 5:
+            break;
+		 default:
+			printf("Wrong choice\n");
+		}
+	}while(choice!=5);
+}
+
+void output_que()
+{	int choice;
+	do
+	{	printf("1.Insert at right\n");
+		printf("2.Insert at left\n");
+		printf("3.Delete from left\n");
+		printf("4.Display\n");
+		printf("5.Quit\n");
+		printf("Enter your choice : ");
+		scanf("%d",&choice);
+		switch(choice)
+		{
+		 case 1:
+			insert_right();
+			break;
+		 case 2:
+			insert_left();
+			break;
+		 case 3:
+			delete_left();
+			break;
+		 case 4:
+			display_queue();
+			break;
+		 case 5:
+			break;
+		 default:
+			printf("Wrong choice\n");
+		}
+	}while(choice!=5);
+}
+
+
+
+main()
+{	int choice;
+	printf("1.Input restricted dequeue\n");
+	printf("2.Output restricted dequeue\n");
+	printf("Enter your choice : ");
+	scanf("%d",&choice);
+	switch(choice)
+	{
+	 case 1 :
+		input_que();
+		break;
+	 case 2:
+		output_que();
+		break;
+	 default:
+		printf("Wrong choice\n");
+	}
+}
+