Deleting a node from linked list 3-ways; using one pointer, two pointers and recursively

delete from linkedlist 3-ways

public class LinkedList {

	private Node head = null;
	
	public LinkedList() {
		head = null;
	}
	
	public void add(int x) {
		if (head == null) {
			head = new Node(x);
		} else {
			Node c = head;
			while (c.next != null) {
				c = c.next;
			}
			c.next = new Node(x);
		}
	}
	
	public void deleteUsingOnePointer(int x) {
		if (head == null) {
			return;
		}
		
		if (head.value == x) {
			head = head.next;
			return;
		}
		
		Node c = head;
		while (c != null) {
			if (c.next != null && c.next.value == x) {
				c.next = c.next.next;
				return;
			} else {
				c = c.next;
			}
		}
	}
	
	public void deleteUsingTwoPointers(int x) {
		
		if (head == null) {
			return;
		}
		
		Node p = null;
		Node c = head;
		
		while (c != null && c.value != x) {
			p = c;
			c = c.next;
		}
		
		if (p == null) {
			head = head.next;
			return;
		} else if (c.value == x) {
			p.next = c.next;
		}
	}
	
	public void deleteRecursive(int x) {
		
		if (head == null) {
			return;
		} else if (head.value == x) {
			head = head.next;
		} else {
			head.next = deleteRecursiveInternal(head.next, x);	
		}
	}
	
	private Node deleteRecursiveInternal(Node n, int x) {
		
		if (n == null) {
			return null;
		}
		
		if (n != null && n.value == x) {
			return n.next;
		} 
		
		n.next = deleteRecursiveInternal(n.next, x);
		
		return n;
	}
	
	public String toString() {
		
		StringBuilder buffer = new StringBuilder();
		
		Node c = head;
		while (c != null) {
			buffer.append(c.value).append(',');
			c = c.next;
		}
		
		if (buffer.length() > 0){
			buffer.delete(buffer.length() -1, buffer.length());
		}
		
		System.out.println(buffer.toString());
		
		return buffer.toString();
	}

	private static class Node {
		Node next;
		int value;
		
		public Node(int value) {
			this.value = value;
		}
	}
}