Added 'Delete' method to Binary Tree
This commit is contained in:
@ -48,6 +48,67 @@ namespace C_.Datastructures.BinaryTree
|
||||
return;
|
||||
}
|
||||
|
||||
public bool Delete(T value)
|
||||
{
|
||||
//Check if root of tree is null
|
||||
if (Count == 0)
|
||||
return false;
|
||||
|
||||
//Check if value is the root
|
||||
if (Count == 1)
|
||||
{
|
||||
if (Root!.Value!.Equals(value))
|
||||
{//If the only item is the one we are trying to delete
|
||||
Count = 0;
|
||||
Root = default;
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
//Stack to store the items leading up to and including the one we are trying to delete
|
||||
Stack<TreeNode<T>>? deletionStack;
|
||||
|
||||
//Search for item being deleted + Parents
|
||||
deletionStack = Find(value);
|
||||
|
||||
if (deletionStack == default)
|
||||
return false; //Item was not found
|
||||
|
||||
//Delete Item (replace) and replace pointers to retain integrity of tree
|
||||
|
||||
TreeNode<T>? node = deletionStack.Pop();
|
||||
TreeNode<T>? parent = deletionStack.Pop();
|
||||
|
||||
//stack to store the items leading up to the value that we will use to replace the node
|
||||
Stack<TreeNode<T>>? replacementStack = Min(node!.Right);
|
||||
if (replacementStack != default)
|
||||
{//If there are values to the right
|
||||
TreeNode<T>? replacementNode = replacementStack.Pop();
|
||||
|
||||
node.Value = replacementNode!.Value;
|
||||
|
||||
//Remove the node that we have taken the value from
|
||||
if (replacementStack.Peek() != default)
|
||||
{//If the parent is not the node that we replaced
|
||||
replacementStack.Pop()!.Left = replacementNode.Right;
|
||||
}else{//If the parent is the node what we replaced
|
||||
node.Right = replacementNode.Right;
|
||||
}
|
||||
}else{
|
||||
//Parent's relation needs to be set to null as there are no greater values
|
||||
if (node.Value!.CompareTo(parent!.Value) < 0)
|
||||
{//Item being deleted is the left child
|
||||
parent.Left = default;
|
||||
}
|
||||
//Item being deleted is the right value
|
||||
parent.Right = default;
|
||||
}
|
||||
Count--;
|
||||
return true;
|
||||
}
|
||||
|
||||
|
||||
private Stack<TreeNode<T>>? Find(T value)
|
||||
{//Return true if the item can be found within the tree
|
||||
if (Root == default || Root.Value!.Equals(default))
|
||||
|
Reference in New Issue
Block a user