/// <summary>
/// Creates a new list in reverse order with the data of current list.
/// List must have atleast one element to perform reverse-clone operation.
/// </summary>
/// <returns>Head node of the newly created list. Null if the list is empty.</returns>
public Singly ReverseClone()
{
if (IsEmpty)
{
return(null);
}
var newSingly = new Singly();
var current = Head;
while (current != null)
{
newSingly.AddFirst(current.Data);
current = current.Next;
}
return(newSingly);
}
/// <summary>
/// Checks if the list is a palindrome or not.
/// </summary>
/// <returns>true if the list is palindrome, false otherwise.</returns>
public bool IsPalindrome()
{
if (IsEmpty)
{
return(false);
}
if (Count == 1)
{
return(true);
}
if (Count == 2 || Count == 3)
{
return(Head.Data == Tail.Data);
}
if (Head.Data != Tail.Data)
{
return(false);
}
var middleNode = IsCountOdd ? InternalGetMiddleNode().Next : InternalGetMiddleNode();
var reverseSecondHalf = new Singly();
while (middleNode != null)
{
reverseSecondHalf.AddFirst(middleNode.Data);
middleNode = middleNode.Next;
}
var reverseCurrent = reverseSecondHalf.Head;
var actualCurrent = Head;
while (reverseCurrent != null)
{
if (reverseCurrent.Data != actualCurrent.Data)
{
return(false);
}
reverseCurrent = reverseCurrent.Next;
actualCurrent = actualCurrent.Next;
}
return(true);
}