Usando punteros, recorra toda la lista y realice un seguimiento del Node anterior al Node que contiene la última clave de ocurrencia usando un puntero especial. Después de esto, simplemente almacene el siguiente del siguiente del puntero especial, en el siguiente del puntero especial para eliminar el Node requerido de la lista vinculada.
C++
#include <iostream> #include <bits/stdc++.h> using namespace std; // A linked list Node struct Node { int data; struct Node* next; }; // Function to delete the last occurrence void deleteLast(struct Node** head, int x) { struct Node** tmp1 = NULL; while (*head) { if ((*head)->data == x) { tmp1 = head; } head = &(*head)->next; } if (tmp1) { struct Node* tmp = *tmp1; *tmp1 = tmp->next; free(tmp); } } // Utility function to create a new node with // given key struct Node* newNode(int x) { Node* node = new Node ; node->data = x; node->next = NULL; return node; } // This function prints contents of linked // list starting from the given Node void display(struct Node* head) { struct Node* temp = head; if (head == NULL) { cout << "NULL\n"; return; } while (temp != NULL) { cout << temp->data <<" --> "; temp = temp->next; } cout << "NULL\n"; } // Driver code int main() { struct Node* head = newNode(1); head->next = newNode(2); head->next->next = newNode(3); head->next->next->next = newNode(4); head->next->next->next->next = newNode(5); head->next->next->next->next->next = newNode(4); head->next->next->next->next->next->next = newNode(4); cout << "Created Linked list: "; display(head); // Pass the address of the head pointer deleteLast(&head, 4); cout << "List after deletion of 4: "; display(head); return 0; } // This code is contributed by khushboogoyal499
C
#include <stdio.h> #include <stdlib.h> // A linked list Node struct Node { int data; struct Node* next; }; // Function to delete the last occurrence void deleteLast(struct Node** head, int x) { struct Node** tmp1 = NULL; while(*head) { if((*head)->data == x) { tmp1 = head; } head = &(*head)->next; } if(tmp1) { struct Node* tmp = *tmp1; *tmp1 = tmp->next; free(tmp); } } /* Utility function to create a new node with given key */ struct Node* newNode(int x) { struct Node* node = malloc(sizeof(struct Node*)); node->data = x; node->next = NULL; return node; } // This function prints contents of linked list // starting from the given Node void display(struct Node* head) { struct Node* temp = head; if (head == NULL) { printf("NULL\n"); return; } while (temp != NULL) { printf("%d --> ", temp->data); temp = temp->next; } printf("NULL\n"); } /* Driver program to test above functions*/ int main() { struct Node* head = newNode(1); head->next = newNode(2); head->next->next = newNode(3); head->next->next->next = newNode(4); head->next->next->next->next = newNode(5); head->next->next->next->next->next = newNode(4); head->next->next->next->next->next->next = newNode(4); printf("Created Linked list: "); display(head); deleteLast(&head, 4); // Pass the address of the head pointer printf("List after deletion of 4: "); display(head); return 0; }
Java
import java.io.*; // A linked list Node class Node { int data; Node next; Node(int data) { this.data = data; this.next = null; } } class GFG{ // Function to delete the last occurrence static Node deleteLast(Node head,int x) { Node temp = head; Node ptr = null; while (temp != null) { // If found key, update if (temp.data == x) ptr = temp; temp = temp.next; } // If the last occurrence is the last node if (ptr != null && ptr.next == null) { temp = head; while (temp.next != ptr) { temp = temp.next; } temp.next = null; } // If it is not the last node if (ptr != null && ptr.next != null) { ptr.data = ptr.next.data; temp = ptr.next; ptr.next = ptr.next.next; } return head; } // This function prints contents of linked list // starting from the given Node static void display(Node head) { Node temp = head; if (head == null) { System.out.print("NULL\n"); return; } while (temp != null) { System.out.print( temp.data+" --> "); temp = temp.next; } System.out.print("NULL\n"); } // Driver code public static void main(String[] args) { Node head = new Node(1); head.next = new Node(2); head.next.next = new Node(3); head.next.next.next = new Node(4); head.next.next.next.next = new Node(5); head.next.next.next.next.next = new Node(4); head.next.next.next.next.next.next = new Node(4); System.out.print("Created Linked list: "); display(head); // Pass the address of the head pointer head = deleteLast(head, 4); System.out.print("List after deletion of 4: "); display(head); } } // This code is contributed by patel2127
C#
// C# program for the above approach using System; public class GFG { // A linked list Node public class Node { public int data; public Node next; public Node(int data) { this.data = data; this.next = null; } } // Function to delete the last occurrence. static Node deleteLast(Node head, int x) { Node temp = head; Node ptr = null; while (temp != null) { // If found key, update if (temp.data == x) ptr = temp; temp = temp.next; } // If the last occurrence is the last node if (ptr != null && ptr.next == null) { temp = head; while (temp.next != ptr) { temp = temp.next; } temp.next = null; } // If it is not the last node if (ptr != null && ptr.next != null) { ptr.data = ptr.next.data; temp = ptr.next; ptr.next = ptr.next.next; } return head; } // This function prints contents of linked list starting // from the given Node. static void display(Node head) { Node temp = head; if (head == null) { Console.Write("NULL\n"); return; } while (temp != null) { Console.Write(temp.data + " --> "); temp = temp.next; } Console.Write("NULL\n"); } static public void Main() { // Code Node head = new Node(1); head.next = new Node(2); head.next.next = new Node(3); head.next.next.next = new Node(4); head.next.next.next.next = new Node(5); head.next.next.next.next.next = new Node(4); head.next.next.next.next.next.next = new Node(4); Console.Write("Created Linked list: "); display(head); // Pass the address of the head pointer head = deleteLast(head, 4); Console.Write("List after deletion of 4: "); display(head); } } // This code is contributed by lokesh (lokeshmvs21).
Python3
# A linked list Node class Node: def __init__(self, new_data): self.data = new_data self.next = None # Function to delete the last occurrence def deleteLast(head, x): temp = head ptr = None while (temp != None): # If found key, update if (temp.data == x): ptr = temp temp = temp.next # If the last occurrence is the last node if (ptr != None and ptr.next == None): temp = head while (temp.next != ptr): temp = temp.next temp.next = None # If it is not the last node if (ptr != None and ptr.next != None): ptr.data = ptr.next.data temp = ptr.next ptr.next = ptr.next.next return head # Utility function to create a new node # with given key def newNode(x): node = Node(0) node.data = x node.next = None return node # This function prints contents of linked # list starting from the given Node def display(head): temp = head if (head == None): print("NULL\n") return while (temp != None): print( temp.data," --> ", end = "") temp = temp.next print("NULL") # Driver code head = newNode(1) head.next = newNode(2) head.next.next = newNode(3) head.next.next.next = newNode(4) head.next.next.next.next = newNode(5) head.next.next.next.next.next = newNode(4) head.next.next.next.next.next.next = newNode(4) print("Created Linked list: ", end = '') display(head) # Pass the address of the head pointer head = deleteLast(head, 4) print("List after deletion of 4: ", end = '') display(head) # This code is contributed by rutvik_56
Javascript
<script> // A linked list Node class Node { // Utility function to create a new node // with given key constructor(data) { this.data = data; this.next = null; } } // Function to delete the last occurrence function deleteLast(head, x) { let temp = head; let prt = null; while (temp != null) { //If found key, update if (temp.data == x) ptr = temp; temp = temp.next; } // If the last occurrence is the last node if (ptr != null && ptr.next == null) { temp = head; while (temp.next != ptr) { temp = temp.next; } temp.next = null; } // If it is not the last node if (ptr != null && ptr.next != null) { ptr.data = ptr.next.data; temp = ptr.next; ptr.next = ptr.next.next; } return head; } // This function prints contents of linked // list starting from the given Node function display(head) { let temp = head if (head == null) { document.write("NULL<br>"); return; } while (temp != null) { document.write( temp.data," --> ", end = ""); temp = temp.next; } document.write("NULL<br>") } // Driver code let head = new Node(1) head.next = new Node(2) head.next.next = new Node(3) head.next.next.next = new Node(4) head.next.next.next.next = new Node(5) head.next.next.next.next.next = new Node(4) head.next.next.next.next.next.next = new Node(4); document.write("Created Linked list: "); display(head) // Pass the address of the head pointer head = deleteLast(head, 4) document.write("List after deletion of 4: ") display(head) // This code is contributed by avanitrachhadiya2155 </script>
Created Linked list: 1 --> 2 --> 3 --> 4 --> 5 --> 4 --> 4 --> NULL List after deletion of 4: 1 --> 2 --> 3 --> 4 --> 5 --> 4 --> NULL
Complejidad de tiempo: O(n)
Espacio Auxiliar: O(1)
Dada una lista enlazada y una clave para ser eliminada. Elimine la última aparición de la clave del enlace. La lista puede tener duplicados.
Ejemplos :
Input: 1->2->3->5->2->10, key = 2 Output: 1->2->3->5->10
La idea es recorrer la lista enlazada de principio a fin. Mientras atraviesa, realice un seguimiento de la última clave de aparición. Después de recorrer la lista completa, elimine la última aparición copiando los datos del siguiente Node y eliminando el siguiente Node.
C++
// A C++ program to demonstrate deletion of last // Node in singly linked list #include <bits/stdc++.h> // A linked list Node struct Node { int key; struct Node* next; }; void deleteLast(Node* head, int key) { // Initialize previous of Node to be deleted Node* x = NULL; // Start from head and find the Node to be // deleted Node* temp = head; while (temp) { // If we found the key, update xv if (temp->key == key) x = temp; temp = temp->next; } // key occurs at-least once if (x != NULL) { // Copy key of next Node to x x->key = x->next->key; // Store and unlink next temp = x->next; x->next = x->next->next; // Free memory for next delete temp; } } /* Utility function to create a new node with given key */ Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->next = NULL; return temp; } // This function prints contents of linked list // starting from the given Node void printList(struct Node* node) { while (node != NULL) { printf(" %d ", node->key); node = node->next; } } /* Driver program to test above functions*/ int main() { /* Start with the empty list */ struct Node* head = newNode(1); head->next = newNode(2); head->next->next = newNode(3); head->next->next->next = newNode(5); head->next->next->next->next = newNode(2); head->next->next->next->next->next = newNode(10); puts("Created Linked List: "); printList(head); deleteLast(head, 2); puts("\nLinked List after Deletion of 2: "); printList(head); return 0; }
Java
// A Java program to demonstrate deletion of last // Node in singly linked list class GFG { // A linked list Node static class Node { int key; Node next; }; static Node deleteLast(Node head, int key) { // Initialize previous of Node to be deleted Node x = null; // Start from head and find the Node to be // deleted Node temp = head; while (temp != null) { // If we found the key, update xv if (temp.key == key) x = temp; temp = temp.next; } // key occurs at-least once if (x != null) { // Copy key of next Node to x x.key = x.next.key; // Store and unlink next temp = x.next; x.next = x.next.next; // Free memory for next } return head; } /// Utility function to create a new node with //given key / static Node newNode(int key) { Node temp = new Node(); temp.key = key; temp.next = null; return temp; } // This function prints contents of linked list // starting from the given Node static void printList( Node node) { while (node != null) { System.out.printf(" %d ", node.key); node = node.next; } } // Driver code/ public static void main(String args[]) { // /Start with the empty list / Node head = newNode(1); head.next = newNode(2); head.next.next = newNode(3); head.next.next.next = newNode(5); head.next.next.next.next = newNode(2); head.next.next.next.next.next = newNode(10); System.out.printf("Created Linked List: "); printList(head); deleteLast(head, 2); System.out.printf("\nLinked List after Deletion of 2: "); printList(head); } } // This code is contributed by Arnab Kundu
Python3
# Python3 program to demonstrate deletion of # last Node in singly linked list # A linked list Node class Node: # Constructor to initialize the node object def __init__(self, data): self.data = data self.next = None def deleteLast(head, key) : # Initialize previous of Node to be deleted x = None # Start from head and find the Node to be # deleted temp = head while (temp != None) : # If we found the key, update xv if (temp.key == key) : x = temp temp = temp.next # key occurs at-least once if (x != None) : # Copy key of next Node to x x.key = x.next.key # Store and unlink next temp = x.next x.next = x.next.next # Free memory for next return head # Utility function to create # a new node with given key def newNode(key) : temp = Node(0) temp.key = key temp.next = None return temp # This function prints contents of linked list # starting from the given Node def printList( node) : while (node != None) : print ( node.key, end = " ") node = node.next # Driver Code if __name__=='__main__': # Start with the empty list head = newNode(1) head.next = newNode(2) head.next.next = newNode(3) head.next.next.next = newNode(5) head.next.next.next.next = newNode(2) head.next.next.next.next.next = newNode(10) print("Created Linked List: ") printList(head) deleteLast(head, 2) print("\nLinked List after Deletion of 2: ") printList(head) # This code is contributed by Arnab Kundu
C#
// C# program to demonstrate deletion of last // Node in singly linked list using System; class GFG { // A linked list Node public class Node { public int key; public Node next; }; static Node deleteLast(Node head, int key) { // Initialize previous of Node to be deleted Node x = null; // Start from head and find the Node to be // deleted Node temp = head; while (temp != null) { // If we found the key, update xv if (temp.key == key) x = temp; temp = temp.next; } // key occurs at-least once if (x != null) { // Copy key of next Node to x x.key = x.next.key; // Store and unlink next temp = x.next; x.next = x.next.next; // Free memory for next } return head; } /// Utility function to create a new node with //given key / static Node newNode(int key) { Node temp = new Node(); temp.key = key; temp.next = null; return temp; } // This function prints contents of linked list // starting from the given Node static void printList( Node node) { while (node != null) { Console.Write(" {0} ", node.key); node = node.next; } } // Driver code public static void Main(String []args) { // Start with the empty list Node head = newNode(1); head.next = newNode(2); head.next.next = newNode(3); head.next.next.next = newNode(5); head.next.next.next.next = newNode(2); head.next.next.next.next.next = newNode(10); Console.Write("Created Linked List: "); printList(head); deleteLast(head, 2); Console.Write("\nLinked List after Deletion of 2: "); printList(head); } } // This code has been contributed by 29AjayKumar
Javascript
<script> // A Javascript program to demonstrate // deletion of last Node in singly // linked list class Node { constructor(key) { this.key = key; this.next = null; } } function deleteLast(head, key) { // Initialize previous of Node to be deleted let x = null; // Start from head and find the Node to be // deleted let temp = head; while (temp != null) { // If we found the key, update xv if (temp.key == key) x = temp; temp = temp.next; } // key occurs at-least once if (x != null) { // Copy key of next Node to x x.key = x.next.key; // Store and unlink next temp = x.next; x.next = x.next.next; // Free memory for next } return head; } // This function prints contents of linked // list starting from the given Node function printList(node) { while (node != null) { document.write(node.key + " "); node = node.next; } } // Driver code let head = new Node(1); head.next = new Node(2); head.next.next = new Node(3); head.next.next.next = new Node(5); head.next.next.next.next = new Node(2); head.next.next.next.next.next = new Node(10); document.write("Created Linked List: <br>"); printList(head); deleteLast(head, 2); document.write("<br>Linked List after " + "Deletion of 2: <br>"); printList(head); // This code is contributed by rag2127 </script>
Created Linked List: 1 2 3 5 2 10 Linked List after Deletion of 2: 1 2 3 5 10
Complejidad de tiempo: O(n)
Espacio Auxiliar: O(1)
La solución anterior no funciona cuando el Node que se eliminará es el último Node.
La siguiente solución maneja todos los casos.
C++
// A C++ program to demonstrate deletion of last // Node in singly linked list #include <bits/stdc++.h> using namespace std; // A linked list Node struct Node { int data; struct Node* next; }; // Function to delete the last occurrence void deleteLast(struct Node* head, int x) { struct Node *temp = head, *ptr = NULL; while (temp) { // If found key, update if (temp->data == x) ptr = temp; temp = temp->next; } // If the last occurrence is the last node if (ptr != NULL && ptr->next == NULL) { temp = head; while (temp->next != ptr) temp = temp->next; temp->next = NULL; } // If it is not the last node if (ptr != NULL && ptr->next != NULL) { ptr->data = ptr->next->data; temp = ptr->next; ptr->next = ptr->next->next; free(temp); } } /* Utility function to create a new node with given key */ struct Node* newNode(int x) { Node* node = new Node ; node->data = x; node->next = NULL; return node; } // This function prints contents of linked list // starting from the given Node void display(struct Node* head) { struct Node* temp = head; if (head == NULL) { cout <<"NULL\n"; return; } while (temp != NULL) { cout <<" --> "<< temp->data; temp = temp->next; } cout <<"NULL\n"; } /* Driver program to test above functions*/ int main() { struct Node* head = newNode(1); head->next = newNode(2); head->next->next = newNode(3); head->next->next->next = newNode(4); head->next->next->next->next = newNode(5); head->next->next->next->next->next = newNode(4); head->next->next->next->next->next->next = newNode(4); cout <<"Created Linked list: "; display(head); deleteLast(head, 4); cout <<"Linked List after deletion of 4: "; display(head); return 0; } // This code is contributed by shivanisinghss2110
C
// A C program to demonstrate deletion of last // Node in singly linked list #include <stdio.h> #include <stdlib.h> // A linked list Node struct Node { int data; struct Node* next; }; // Function to delete the last occurrence void deleteLast(struct Node* head, int x) { struct Node *temp = head, *ptr = NULL; while (temp) { // If found key, update if (temp->data == x) ptr = temp; temp = temp->next; } // If the last occurrence is the last node if (ptr != NULL && ptr->next == NULL) { temp = head; while (temp->next != ptr) temp = temp->next; temp->next = NULL; } // If it is not the last node if (ptr != NULL && ptr->next != NULL) { ptr->data = ptr->next->data; temp = ptr->next; ptr->next = ptr->next->next; free(temp); } } /* Utility function to create a new node with given key */ struct Node* newNode(int x) { struct Node* node = malloc(sizeof(struct Node*)); node->data = x; node->next = NULL; return node; } // This function prints contents of linked list // starting from the given Node void display(struct Node* head) { struct Node* temp = head; if (head == NULL) { printf("NULL\n"); return; } while (temp != NULL) { printf("%d --> ", temp->data); temp = temp->next; } printf("NULL\n"); } /* Driver program to test above functions*/ int main() { struct Node* head = newNode(1); head->next = newNode(2); head->next->next = newNode(3); head->next->next->next = newNode(4); head->next->next->next->next = newNode(5); head->next->next->next->next->next = newNode(4); head->next->next->next->next->next->next = newNode(4); printf("Created Linked list: "); display(head); deleteLast(head, 4); printf("List after deletion of 4: "); display(head); return 0; }
Java
// Java program to demonstrate deletion of last // Node in singly linked list class GFG { // A linked list Node static class Node { int data; Node next; }; // Function to delete the last occurrence static void deleteLast(Node head, int x) { Node temp = head, ptr = null; while (temp!=null) { // If found key, update if (temp.data == x) ptr = temp; temp = temp.next; } // If the last occurrence is the last node if (ptr != null && ptr.next == null) { temp = head; while (temp.next != ptr) temp = temp.next; temp.next = null; } // If it is not the last node if (ptr != null && ptr.next != null) { ptr.data = ptr.next.data; temp = ptr.next; ptr.next = ptr.next.next; System.gc(); } } /* Utility function to create a new node with given key */ static Node newNode(int x) { Node node = new Node(); node.data = x; node.next = null; return node; } // This function prints contents of linked list // starting from the given Node static void display(Node head) { Node temp = head; if (head == null) { System.out.print("null\n"); return; } while (temp != null) { System.out.printf("%d --> ", temp.data); temp = temp.next; } System.out.print("null\n"); } /* Driver code*/ public static void main(String[] args) { Node head = newNode(1); head.next = newNode(2); head.next.next = newNode(3); head.next.next.next = newNode(4); head.next.next.next.next = newNode(5); head.next.next.next.next.next = newNode(4); head.next.next.next.next.next.next = newNode(4); System.out.print("Created Linked list: "); display(head); deleteLast(head, 4); System.out.print("List after deletion of 4: "); display(head); } } /* This code is contributed by PrinciRaj1992 */
Python3
# A Python3 program to demonstrate deletion of last # Node in singly linked list # A linked list Node class Node: def __init__(self, new_data): self.data = new_data self.next = None # Function to delete the last occurrence def deleteLast(head, x): temp = head ptr = None while (temp!=None): # If found key, update if (temp.data == x) : ptr = temp temp = temp.next # If the last occurrence is the last node if (ptr != None and ptr.next == None): temp = head while (temp.next != ptr) : temp = temp.next temp.next = None # If it is not the last node if (ptr != None and ptr.next != None): ptr.data = ptr.next.data temp = ptr.next ptr.next = ptr.next.next return head # Utility function to create a new node with # given key def newNode(x): node = Node(0) node.data = x node.next = None return node # This function prints contents of linked list # starting from the given Node def display( head): temp = head if (head == None): print("None\n") return while (temp != None): print( temp.data," -> ",end="") temp = temp.next print("None") # Driver code head = newNode(1) head.next = newNode(2) head.next.next = newNode(3) head.next.next.next = newNode(4) head.next.next.next.next = newNode(5) head.next.next.next.next.next = newNode(4) head.next.next.next.next.next.next = newNode(4) print("Created Linked list: ") display(head) head = deleteLast(head, 4) print("List after deletion of 4: ") display(head) # This code is contributed by Arnab Kundu
C#
// C# program to demonstrate deletion of last // Node in singly linked list using System; class GFG { // A linked list Node public class Node { public int data; public Node next; }; // Function to delete the last occurrence static void deleteLast(Node head, int x) { Node temp = head, ptr = null; while (temp != null) { // If found key, update if (temp.data == x) ptr = temp; temp = temp.next; } // If the last occurrence is the last node if (ptr != null && ptr.next == null) { temp = head; while (temp.next != ptr) temp = temp.next; temp.next = null; } // If it is not the last node if (ptr != null && ptr.next != null) { ptr.data = ptr.next.data; temp = ptr.next; ptr.next = ptr.next.next; } } /* Utility function to create a new node with given key */ static Node newNode(int x) { Node node = new Node(); node.data = x; node.next = null; return node; } // This function prints contents of linked list // starting from the given Node static void display(Node head) { Node temp = head; if (head == null) { Console.Write("null\n"); return; } while (temp != null) { Console.Write("{0} --> ", temp.data); temp = temp.next; } Console.Write("null\n"); } /* Driver code*/ public static void Main(String[] args) { Node head = newNode(1); head.next = newNode(2); head.next.next = newNode(3); head.next.next.next = newNode(4); head.next.next.next.next = newNode(5); head.next.next.next.next.next = newNode(4); head.next.next.next.next.next.next = newNode(4); Console.Write("Created Linked list: "); display(head); deleteLast(head, 4); Console.Write("List after deletion of 4: "); display(head); } } // This code contributed by Rajput-Ji
Javascript
<script> // JavaScript program to demonstrate // deletion of last // Node in singly linked list // A linked list Node class Node { constructor() { this.data = 0; this.next = null; } } // Function to delete the last occurrence function deleteLast(head , x) { var temp = head, ptr = null; while (temp != null) { // If found key, update if (temp.data == x) ptr = temp; temp = temp.next; } // If the last occurrence is the last node if (ptr != null && ptr.next == null) { temp = head; while (temp.next != ptr) temp = temp.next; temp.next = null; } // If it is not the last node if (ptr != null && ptr.next != null) { ptr.data = ptr.next.data; temp = ptr.next; ptr.next = ptr.next.next; } } /* Utility function to create a new node with given key */ function newNode(x) { var node = new Node(); node.data = x; node.next = null; return node; } // This function prints contents of linked list // starting from the given Node function display(head) { var temp = head; if (head == null) { document.write("null<br/>"); return; } while (temp != null) { document.write( temp.data + " --> "); temp = temp.next; } document.write("null<br/>"); } /* Driver code */ var head = newNode(1); head.next = newNode(2); head.next.next = newNode(3); head.next.next.next = newNode(4); head.next.next.next.next = newNode(5); head.next.next.next.next.next = newNode(4); head.next.next.next.next.next.next = newNode(4); document.write("Created Linked list: "); display(head); deleteLast(head, 4); document.write("List after deletion of 4: "); display(head); // This code contributed by gauravrajput1 </script>
Created Linked list: --> 1 --> 2 --> 3 --> 4 --> 5 --> 4 --> 4NULL Linked List after deletion of 4: --> 1 --> 2 --> 3 --> 4 --> 5 --> 4NULL
Complejidad de tiempo: O(n)
Espacio auxiliar: O(1)
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Artículo escrito por GeeksforGeeks-1 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA