circular_linked_list.go

package main

import "fmt"

type Node struct {
    data interface{}
    next *Node
}

type CircularLinkedList struct {
    head *Node
}

func (list *CircularLinkedList) IsEmpty() bool {
    return list.head == nil
}

func (list *CircularLinkedList) InsertAtHead(data interface{}) {
    new := &Node{data: data}
    if list.IsEmpty() {
        list.head = new
        new.next = list.head
    } else {
        current := list.head
        for current.next != list.head {
            current = current.next
        }
        current.next = new
        new.next = list.head
        list.head = new
    }
}

func (list *CircularLinkedList) InsertAtTail(data interface{}) {
    new := &Node{data: data}
    if list.IsEmpty() {
        list.head = new
        new.next = list.head
    } else {
        current := list.head
        for current.next != list.head {
            current = current.next
        }
        current.next = new
        new.next = list.head
    }
}

func (list *CircularLinkedList) Delete(data interface{}) {
    if list.IsEmpty() {
        fmt.Println("Linked list is empty. No node to delete.")
    } else if list.head.data == data {
        current := list.head
        for current.next != list.head {
            current = current.next
        }
        current.next = list.head.next
        list.head = list.head.next
    } else {
        current := list.head
        var prev *Node
        for current.next != list.head {
            if current.data == data {
                prev.next = current.next
                return
            }
            prev = current
            current = current.next
        }
        if current.data == data {
            prev.next = list.head
        }
    }
}

func (list *CircularLinkedList) Display() {
    if list.IsEmpty() {
        fmt.Println("Linked list is empty.")
    } else {
        current := list.head
        for {
            fmt.Print(current.data, " ")
            current = current.next
            if current == list.head {
                break
            }
        }
        fmt.Println()
    }
}

// Usage example:
func main() {
    linkedList := &CircularLinkedList{}
    linkedList.InsertAtHead(5)
    linkedList.InsertAtHead(3)
    linkedList.InsertAtTail(7)
    linkedList.Display()  // Output: 3 5 7
    linkedList.Delete(3)
    linkedList.Display()  // Output: 5 7
}