Create Deque

Deque

@@ -0,0 +1,172 @@
+#include<stdio.h>
+#define MAX 10
+
+int deque[MAX];
+int left=-1, right=-1;
+
+void insert_right(void);
+void insert_left(void);
+void delete_right(void);
+void delete_left(void);
+void display(void);
+
+int main()
+{
+ int choice;
+ do
+ {
+  printf("\n1.Insert at right ");
+  printf("\n2.Insert at left ");
+  printf("\n3.Delete from right ");
+  printf("\n4.Delete from left ");
+  printf("\n5.Display ");
+  printf("\n6.Exit");
+  printf("\n\nEnter your choice ");
+  scanf("%d",&choice);
+  switch(choice)
+  {
+   case 1:
+    insert_right();
+    break;
+   case 2:
+    insert_left();
+    break;
+   case 3:
+    delete_right();
+    break;
+   case 4:
+    delete_left();
+    break;
+   case 5:
+    display();
+    break;
+  }
+ }while(choice!=6);
+ return 0;
+}
+//INSERT AT RIGHT
+void insert_right()
+{
+ int val;
+ printf("\nEnter the value to be added ");
+ scanf("%d",&val);
+ if( (left==0 && right==MAX-1) || (left==right+1) )
+ {
+  printf("\nOVERFLOW");
+ }
+ if(left==-1)        //if queue is initially empty
+ {
+  left=0;
+  right=0;
+ }
+ else
+ {
+  if(right==MAX-1)
+   right=0;
+  else
+   right=right+1;
+ }
+ deque[right]=val;
+}
+//INSERT AT LEFT
+void insert_left()
+{
+ int val;
+ printf("\nEnter the value to be added ");
+ scanf("%d",&val);
+ if( (left==0 && right==MAX-1) || (left==right+1) )
+ {
+  printf("\nOVERFLOW");
+ }
+ if(left==-1)        //if queue is initially empty
+ {
+  left=0;
+  right=0;
+ }
+ else
+ {
+  if(left==0)
+   left=MAX-1;
+  else
+   left=left-1;
+ }
+ deque[left]=val;
+}
+//DELETE FROM RIGHT
+void delete_right()
+{
+ if(left==-1)
+ {
+  printf("\nUNDERFLOW");
+  return;
+ }
+ printf("\nThe deleted element is %d\n", deque[right]);
+ if(left==right)          //Queue has only one element
+ {
+  left=-1;
+  right=-1;
+ }
+ else
+ {
+  if(right==0)
+   right=MAX-1;
+  else
+   right=right-1;
+ }
+}
+//DELETE FROM LEFT
+void delete_left()
+{
+ if(left==-1)
+ {
+  printf("\nUNDERFLOW");
+  return;
+ }
+ printf("\nThe deleted element is %d\n", deque[left]);
+ if(left==right)          //Queue has only one element
+ {
+  left=-1;
+  right=-1;
+ }
+ else
+ {
+  if(left==MAX-1)
+   left=0;
+  else
+   left=left+1;
+ }
+}
+//DISPLAY
+void display()
+{
+ int front=left, rear=right;
+ if(front==-1)
+ {
+  printf("\nQueue is Empty\n");
+  return;
+ }
+ printf("\nThe elements in the queue are: ");
+ if(front<=rear)
+ {
+  while(front<=rear)
+  {
+   printf("%d\t",deque[front]);
+   front++;
+  }
+ }
+ else
+ {
+  while(front<=MAX-1)
+  {
+   printf("%d\t",deque[front]);
+   front++;
+  }
+  front=0;
+  while(front<=rear)
+  {
+   printf("%d\t",deque[front]);
+   front++;
+  }
+ }
+ printf("\n");
+}