Title here
Summary here
03 - Circular Singly Linked List -(Own Implementation)
Final Implementation
Refer to Doubly Circular List and Doubly Linked List for Break down of logic and Reasons for the code.
#include <stdio.h>
#include <stdlib.h>
struct node
{
int data;
struct node *next;
}*head = NULL, *tail = NULL, *new=NULL;
void Inserter(int ch, int ele);
void Deleter(int ch);
void Display();
void Search();
int length();
int main()
{
int ch, ele;
while(1)
{
printf("\n1. Insert at Beginning\t2. Insert inBetween\t3. Insert at End\n");
printf("4. Delete Beginning\t5. Delete inBetween\t6. Delete End\n");
printf("7. Display\t8. Search\t0. Exit\n");
printf("Enter a Choice: ");
scanf("%d", &ch);
printf("\n");
switch(ch)
{
case 0:
exit(0);
case 1:
case 2:
case 3:
printf("\nEnter the value to Insert: ");
scanf("%d", &ele);
Inserter(ch, ele);
Display();
break;
case 4:
case 5:
case 6:
Deleter(ch);
Display();
break;
case 7:
Display();
printf("\nLength is: %d\n", length());
break;
case 8:
Search();
break;
}
}
return 0;
}
void firstNode(int ele)
{
new = (struct node*) malloc(sizeof(struct node));
new->data = ele;
new->next = new;
head = tail = new;
}
void inB(int ele)
{
new = (struct node*) malloc(sizeof(struct node));
new->data = ele;
new->next = head;
tail->next = new;
head = new;
}
void inE(int ele)
{
new = (struct node*) malloc(sizeof(struct node));
new->data = ele;
new->next = head;
tail->next = new;
tail = new;
}
int length()
{
if(head == NULL)
return 0;
if(head == tail)
return 1;
struct node *temp = head;
int len = 0;
while(temp != tail)
{
len++;
temp = temp->next;
}
len++;
return len;
}
int getPos()
{
int len = length();
int pos;
printf("\nEnter Position: ");
scanf("%d", &pos);
if(pos <= 0 || pos > len+1)
{
printf("\nInvalid Location\n");
return -1;
}
return pos;
}
void inM(int ele)
{
int pos = getPos();
int len = length();
if(pos == -1)
return;
if(pos == 1)
{
inB(ele);
return;
}
if(pos == len+1)
{
inE(ele);
return;
}
struct node *temp = head;
for(int i=2; i<pos ; i++)
{
temp = temp->next;
}
new = (struct node*) malloc(sizeof(struct node));
new->data = ele;
new->next = temp->next;
temp->next = new;
}
void Inserter(int ch, int ele)
{
if(head == NULL)
{
firstNode(ele);
return;
}
switch(ch)
{
case 1:
inB(ele);
break;
case 2:
inM(ele);
break;
case 3:
inE(ele);
break;
}
}
void Display()
{
if(head == NULL)
{
printf("\nNothing to Display\n");
return;
}
int len = length();
struct node *temp = head;
for(int i = 0; i<len ; i++)
{
printf("%d -> ", temp->data);
temp = temp->next;
}
printf(" Head\n\nList has %d Nodes", len );
}
void delB()
{
struct node *temp = head;
head = head->next;
tail->next = head;
free(temp);
}
void delE()
{
// Need two Nodes to delete
struct node* temp = tail;
struct node *tempPrev = head;
int len = length();
// using i=2, starts from head, stop just before Tail
// Gives Node just before Tail
for(int i=2 ; i<len ; i++ )
{
tempPrev = tempPrev->next;
}
// while( tempPrev->next != tail)
// { tempPrev = tempPrev->next;}
tail = tempPrev;
tail->next = head;
free(temp);
}
void delM()
{
int pos = getPos();
int len = length();
if(pos == -1 || pos == len+1)
return;
if(pos == 1)
{
delB();
return;
}
if(pos == len)
{
delE();
return;
}
struct node *temp = head;
for (int i=2; i<pos; i++)
{
temp = temp->next;
}
// Node Next to temp has to be deleted
struct node *delNode = temp->next;
temp->next = delNode->next;
free(delNode);
}
void Deleter(int ch)
{
if(head == NULL)
{
printf("\nNothing to Delete\n");
return;
}
if(head == tail)
{
struct node *temp = head;
head = tail = NULL;
free(temp);
return;
}
switch(ch)
{
case 4:
delB();
break;
case 5:
delM();
break;
case 6:
delE();
break;
}
}
void Search()
{
if(head == NULL)
{
printf("\nNo elements to search\n");
return;
}
int ele;
printf("\nEnter the number to be Searched: ");
scanf("%d", &ele);
int found = 0;
struct node *temp = head;
for(int i=0 ; i<length() ; i++ )
{
if (temp->data == ele)
{
printf("\nElement %d found at index %d\n", ele, i);
found =1;
break;
}
temp = temp->next;
}
// if found still 0, No Match Found
if(!found)
printf("\nElement %d was not found.\n", ele);
}Almost Final
#include <stdio.h>
#include <stdlib.h>
struct node
{
int data;
struct node *next;
}*head = NULL, *tail = NULL, *new=NULL;
void Inserter(int ch, int ele);
void Deleter(int ch);
void Display();
void Search();
int length();
int getPos();
int main()
{
int ch, ele;
while(1)
{
printf("\n1. Insert at Beginning\t2. Insert inBetween\t3. Insert at End\n");
printf("4. Delete Beginning\t5. Delete inBetween\t6. Delete End\n");
printf("7. Display\t8. Search\t0. Exit\n");
printf("Enter a Choice: ");
scanf("%d", &ch);
printf("\n");
switch(ch)
{
case 0:
exit(0);
case 1:
case 2:
case 3:
printf("\nEnter the value to Insert: ");
scanf("%d", &ele);
Inserter(ch, ele);
Display();
break;
case 4:
case 5:
case 6:
Deleter(ch);
Display();
break;
case 7:
Display();
printf("\nLength is: %d\n", length());
break;
case 8:
Search();
break;
}
}
return 0;
}
void firstNode(int ele)
{
new = (struct node*) malloc(sizeof(struct node));
new->data = ele;
new->next = new;
head = new;
tail = new;
}
void inB(int ele)
{
new = (struct node*) malloc(sizeof(struct node));
new->data = ele;
new->next = head;
tail->next = new;
head = new;
}
void inE(int ele)
{
new = (struct node*) malloc(sizeof(struct node));
new->data = ele;
tail->next = new;
new->next = head;
tail = new;
}
int length()
{
if(head == NULL)
return 0;
if(head == tail)
return 1;
struct node *temp = head;
int len = 0;
while(temp != tail)
{
temp = temp->next;
len++;
}
len++;
return len;
}
int getPos()
{
int len = length();
int pos;
printf("\nEnter Position: ");
scanf("%d", &pos);
if(pos <= 0 || pos > len+1)
{
printf("\nInvalid Location\n");
return -1;
}
return pos;
}
void inM(int ele)
{
int pos = getPos();
if(pos == -1)
return;
if(pos == 1)
{
inB(ele);
return;
}
if(pos == length()+1)
{
inE(ele);
return;
}
int i = 2;
struct node *temp = head;
while(i < pos)
{
temp = temp->next;
i++;
}
new = (struct node*) malloc(sizeof(struct node));
new->data = ele;
new->next = temp->next;
temp->next = new;
}
void Inserter(int ch, int ele)
{
if(head == NULL)
{
firstNode(ele);
return;
}
switch(ch)
{
case 1:
inB(ele);
break;
case 2:
inM(ele);
break;
case 3:
inE(ele);
break;
}
}
void delB()
{
struct node *temp = head;
head = head->next;
tail->next = head;
free(temp);
}
void delE()
{
struct node *tailPrev = head;
while(tailPrev->next != tail)
{
tailPrev = tailPrev->next;
}
struct node* temp = tail;
tailPrev->next = head;
tail = tailPrev;
free(temp);
}
void delM()
{
int pos = getPos();
if(pos == -1 || pos == length()+1)
return;
if(pos == 1)
{
delB();
return;
}
if(pos == length())
{
delE();
return;
}
int i = 2;
struct node *temp = head;
while( i < pos)
{
temp = temp->next;
i++;
}
for (int i =2; i <pos; i++)
{
temp = temp->next
}
struct node *delNode = temp->next;
temp->next = delNode->next;
free(delNode);
}
void Deleter(int ch)
{
if(head == NULL)
{
printf("\nNothing to Delete\n");
return;
}
if(head == tail)
{
struct node *temp = head;
head = tail = NULL;
free(temp);
return;
}
switch(ch)
{
case 4:
delB();
break;
case 5:
delM();
break;
case 6:
delE();
break;
}
}
void Display()
{
if(head == NULL)
{
printf("\nNothing to Display\n");
return;
}
struct node *temp = head;
while(temp != tail)
{
printf("%d -> ", temp->data);
temp = temp->next;
}
printf("%d", temp->data);
printf("\nList has %d Nodes", length());
}
void Search()
{
if(head == NULL)
{
printf("\nNo elements to search\n");
return;
}
int ele;
printf("\nEnter the number to be Searched: ");
scanf("%d", &ele);
struct node *temp = head;
int pos = 1;
while(temp != tail)
{
if(temp->data == ele)
{
printf("\nElement %d was found at position %d\n", ele, pos);
return;
}
temp = temp->next;
pos++;
}
if(temp->data == ele)
{
printf("\nElement %d was found at position %d\n", ele, pos);
return;
}
printf("\nElement %d was not found\n", ele);
}#include <stdio.h>
#include <stdlib.h>
struct node
{
int data;
struct node *next;
}*head=NULL, *new=NULL;
int len;
void Begin(int a)
{
struct node *temp;
new = (struct node*)malloc(sizeof(struct node));
new->data = a;
if (head == NULL)
{
head = new;
new->next = head; // Circular connection
}
else
{
temp = head;
while (temp->next != head)
{
temp = temp->next;
}
new->next = head; // New node points to the current head
temp->next = new; // Last node points to the new node
head = new; // Update head to new node
}
}
void End(int a)
{
struct node *temp;
new = (struct node*)malloc(sizeof(struct node));
new->data = a;
if (head == NULL)
{ // If the list is empty
head = new;
new->next = head; // Circular connection
}
else
{
temp = head;
while (temp->next != head)
{ // Traverse to the last node
temp = temp->next;
}
temp->next = new; // Last node points to new node
new->next = head; // New node points back to head (circular)
}
}
int length()
{
struct node *temp = head;
int count = 0;
if (head == NULL)
{
return 0; // If the list is empty, length is 0
}
while (temp->next != head)
{
count++;
temp = temp->next;
}
count++;
return count;
}
void Display()
{
struct node *temp;
if (head == NULL)
{
printf("The List is Empty\n");
return;
}
temp = head;
printf("Circular Linked List: ");
while (temp->next != head)
{
printf("%d --> ", temp->data);
temp = temp->next;
}
printf("%d --> (back to head)\n\n", temp->data);
len = length();
printf("The Total Elements == %d\n", len);
}
void Middle(int a)
{
struct node *newNode, *temp;
int loc, i = 1;
len = length();
if (len == 0)
{
printf("The list is empty. Cannot insert in the middle.\n");
return;
}
printf("Enter the location to be inserted: ");
scanf("%d", &loc);
if (loc > len || loc < 1) // Ensure the position is valid
{
printf("Invalid Location\n");
return;
}
temp = head;
while (i < loc) // Traverse to the node before the desired position
{
temp = temp->next;
i++;
}
new = (struct node*)malloc(sizeof(struct node));
new->data = a;
new->next = temp->next;
temp->next = new;
printf("Node inserted successfully at position %d\n", loc);
}
void Search(int key)
{
struct node *temp = head;
int pos = 1, found = 0;
if (head == NULL)
{
printf("The list is empty. Cannot search.\n");
return;
}
while (temp->next != head)
{ // Traverse until the last node
if (temp->data == key)
{
printf("Element %d found at position %d\n", key, pos);
found = 1;
break;
}
temp = temp->next;
pos++;
}
// Check the last node after exiting the loop
if (temp->data == key && !found)
{
printf("Element %d found at position %d\n", key, pos);
found = 1;
}
}
void DBegin()
{
struct node *temp, *last;
if (head == NULL) // Check if the list is empty
{
printf("The list is empty. Cannot delete.\n");
return;
}
if (head->next == head) // If there's only one node in the list
{
free(head);
head = NULL;
printf("The last node is deleted, and the list is now empty.\n");
return;
}
temp = head;
// Find the last node in the circular linked list
last = head;
while (last->next != head)
{
last = last->next;
}
// Update head to the next node
head = head->next;
last->next = head; // Maintain circularity
free(temp); // Delete the old head
printf("First node deleted successfully.\n");
}
void DMid()
{
struct node *temp, *nextnode;
int loc, i = 1;
len = length();
if (len == 0) {
printf("The list is empty. Cannot delete.\n");
return;
}
printf("Please enter the position to delete: ");
scanf("%d", &loc);
if (loc > len || loc < 1) {
printf("Invalid Location\n");
return;
}
// If deleting the first node (use separate function for head deletion)
if (loc == 1) {
DBegin(); // Call the function to delete from the beginning
return;
}
temp = head;
while (i < loc - 1) // Traverse to the node before the one to be deleted
{
temp = temp->next;
i++;
}
nextnode = temp->next; // Node to be deleted
temp->next = nextnode->next; // Adjust the link to skip the deleted node
free(nextnode); // Free the memory of the deleted node
printf("Node at position %d deleted successfully.\n", loc);
}
void DEnd()
{
struct node *temp = head, *prev;
if (head == NULL) // Check if the list is empty
{
printf("The list is empty, nothing to delete.\n");
return;
}
// If there is only one node in the list
if (head->next == head)
{
free(head);
head = NULL;
printf("Last node deleted, list is now empty.\n");
return;
}
// Traverse to the second last node
while (temp->next != head) {
prev = temp;
temp = temp->next;
}
prev->next = head; // Update second last node to point to head (maintain circularity)
free(temp); // Free memory of the last node
printf("Last node deleted successfully.\n");
}
void main()
{
int a;
while(1)
{
int ch;
printf("\n1.Insert Begining\n");
printf("2. Insert Middle \n");
printf("3. Insert End \n");
printf("4. Display \n");
printf("5. Search \n");
printf("6. Delete Begining \n");
printf("7. Delete Middle \n");
printf("8. Delete End \n");
printf("\nEnter choice: ");
scanf("%d",&ch);
switch(ch)
{
case 1:
printf("Enter the element to be inserted \n");
scanf("%d", &a);
Begin(a);
break;
case 2:
printf("Enter the element to be inserted \n");
scanf("%d", &a);
Middle(a);
break;
case 3:
printf("Enter the element to be inserted \n");
scanf("%d", &a);
End(a);
break;
case 4: Display();
break;
case 5: // Search case
printf("Enter the element to search: \n");
scanf("%d", &a);
Search(a);
break;
case 6: DBegin();
break;
case 7: DMid();
break;
case 8: DEnd();
break;
default:
printf("Enter the choice Correctly\n");
break;
}
}
}