// This is a practice on how to solve a problem -> need to look for opportunities to discuss your solutions out loud
public SingleLinkedListNode <T> CreateNewHead() // This will return a new head
{
// Verify if Head is null -> return null if it is -> O(1)
var current = Head;
if (current == null)
{
return(null);
}
// Create a new head -> this will take the data from the head
var newHead = new SingleLinkedListNode <T>(current.Data);
// Create a pointer to the current node -> Head next node
current = current.NextNode;
var newTempNode = newHead; // this is pointing to the same memory reference
// Loop though the next nodes while it is not null O(n) -> time
while (current != null)
{
// assing the next node to the new head -> we want to new this up
newTempNode.NextNode = new SingleLinkedListNode <T>(current.Data); // O(n) -> spacial
// change the current to the next node
current = current.NextNode;
// move the temp node to the next node
newTempNode = newTempNode.NextNode;
}
return(newHead); // After done, always make sure to ask for feedback and tell that you're don
}
public void Prepend(T data)
{
var newHead = new SingleLinkedListNode <T>(data);
newHead.NextNode = Head;
Head = newHead;
}
// TODO: There is also a recursive approach to reverse
public void Reverse()
{
var current = Head;
SingleLinkedListNode <T> next = null;
SingleLinkedListNode <T> prev = null;
while (current != null)
{
next = current.NextNode;
current.NextNode = prev;
prev = current;
current = next;
}
}
} // TODO: Implement
public void Append(T data)
{
if (Head == null)
{
Head = new SingleLinkedListNode <T>(data);
return;
}
var currentNode = Head;
while (currentNode.NextNode != null)
{
currentNode = currentNode.NextNode;
}
currentNode.NextNode = new SingleLinkedListNode <T>(data);
}
public void InsertAt(T data, int insertIndex)
{
// Option #1
if (Head == null)
{
Head = new SingleLinkedListNode <T>(data);
return;
}
var current = Head;
var index = 1;
while (current.NextNode != null && index < insertIndex)
{
current = current.NextNode;
index++;
}
var newInsertNode = new SingleLinkedListNode <T>(data); // We create the new node with the data that was passed
newInsertNode.NextNode = current.NextNode; // We assigin the newInsetNode.NextNode to the next node from the previous node
// Another way
//var newInsertNode = new SingleLinkedListNode<T>(data) { NextNode = current.NextNode };
current.NextNode = newInsertNode; // Now the current next node can be assign the new node
// Option #2
//if (Head == null)
//{
// Head = new SingleLinkedListNode<T>(data);
// return;
//}
//var current = Head;
//var newHead = new SingleLinkedListNode<T>(Head.Data);
//var newTail = newHead;
//current = current.NextNode;
//var index = 1;
//while (current != null)
//{
// if (index == insertIndex)
// {
// var newNode = new SingleLinkedListNode<T>(data);
// newNode.NextNode = current;
// current = newNode;
// }
// newTail.NextNode = new SingleLinkedListNode<T>(current.Data); // This will append to the next node of the tail
// newTail = newTail.NextNode; // Now that the old tail's next node has been assigned, we move the reference of the tail to the new node
// current = current.NextNode;
// index++;
//}
}
