Added circular linked list menu driven program

menu_drive_circular_linked_list.c

@@ -0,0 +1,208 @@
+#include<stdio.h>
+#include<stdlib.h>
+
+typedef struct node
+{
+    int data;
+    struct node *next;
+}node;
+
+node *head=NULL;
+
+void Insertionatbeginning()
+{
+    node *temp;
+    temp=(node *)malloc(sizeof(node));
+    printf("\nEnter data: ");
+    scanf("%d",&temp->data);
+    temp->next=NULL;
+    if(head==NULL)
+    {
+        temp->next=temp;
+        head=temp;
+    }
+    else
+    {
+        temp->next=head->next;
+        head->next=temp;
+    }
+}
+void Insertionatlast()
+{
+    node* temp;
+    temp = (node*)malloc(sizeof(node));
+    printf("\nEnter data: ");
+    scanf("%d",&temp->data);
+    if (head == NULL)
+    {
+        temp->next = temp;
+        head = temp;
+    }
+    else 
+    {
+        temp->next = head->next;
+        head->next = temp;
+        head = temp;
+    }
+}
+void Insertionatindex()
+{
+    node *temp,*ptr;
+    int pos,k=1;
+    ptr=head->next;
+    printf("\nEnter index of node to Insert: ");
+    scanf("%d",&pos);
+    while(k<pos-1)
+    {
+        ptr=ptr->next;
+        k++;
+    }
+    if(ptr==head)
+        printf("\nNo. of nodes are less than the position");
+    else
+    {
+        temp=(node*)malloc(sizeof(node));
+        printf("\nEnter data: ");
+        scanf("%d",&temp->data);
+        temp->next=ptr->next;
+        ptr->next=temp;
+    }
+}
+void deleteatfirst()
+{
+    node* temp;
+    if (head == NULL)
+        printf("\nList is empty.\n");
+    else {
+        temp = head->next;
+        head->next = temp->next;
+        free(temp);
+    }
+}
+void deleteatlast()
+{
+    struct node* temp;
+    if (head == NULL)
+        printf("\nList is empty.\n");
+
+    temp = head->next;
+    while (temp->next != head)
+        temp = temp->next;
+    temp->next = head->next;
+    head = temp;
+}
+void deleteatIndex()
+{
+    if (head == NULL)
+        printf("\nList is empty!\n");
+    else 
+    {
+        int pos, i = 1;
+        node *temp, *position;
+        temp = head;
+        printf("\nEnter index of node to be deleted: ");
+        scanf("%d", &pos);
+        while (i <= pos - 1) 
+        {
+            temp = temp->next;
+            i++;
+        }
+        position = temp->next;
+        temp->next = position->next;
+    }
+}
+void search()
+{
+    if(head==NULL)
+        printf("\nList is Empty!");
+    else
+    {
+        int k,i=1;
+        printf("\nEnter element to search: ");
+        scanf("%d",&k);
+        node *temp;
+        temp=head->next;
+        while(temp->next != head) 
+        {
+            if(temp->data == k) 
+            {
+                printf("%d found at position %d\n",k,i);
+                return;
+            }
+
+            temp = temp->next;
+            i++;
+        }
+
+        if(temp->data == k) 
+        {
+            printf("%d found at position %d\n",k,i);
+            return;
+        }
+
+        printf("\nElement not found");
+    }
+}
+void Display()
+{
+    if(head==NULL)
+    {
+        printf("\nList is Empty\n");
+    }
+    else
+    {
+        node *temp;
+        temp=head->next;
+        do
+        {
+            printf("-->%d",temp->data);
+            temp=temp->next;
+        } while (temp!=head->next);
+
+    }
+}
+
+int main()
+{
+    int m=-1;
+    while(m!=0)
+    {
+        printf("\n*********Menu Drive Circular Linked list*********\n");  
+        printf("\nChoose one option from the following list ...\n");
+        printf("\nEnter Option:\n0-Exit\n1-Insertion at the beginning\n2-Insertion at the end\n3-Insertion at given position\n4-Deletion at the beginning\n");
+        printf("5-Deletion at the end\n6-Deletion at the given position\n7-Search\n8-Display\n");
+        scanf("%d",&m);
+        switch (m)
+        {
+        case 0:
+            break;
+        case 1:
+            Insertionatbeginning();
+            break;
+        case 2:
+            Insertionatlast();
+            break;
+        case 3:
+            Insertionatindex();
+            break;
+        case 4:
+            deleteatfirst();
+            break;
+        case 5:
+            deleteatlast();
+            break;
+        case 6:
+            deleteatIndex();
+            break;
+        case 7:
+            search();
+            break;
+        case 8:
+            Display();
+            break;
+        default:
+            break;
+        }
+    }
+    return 0;
+}