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authorBenjamin J. Culkin <bjculkin@mix.wvu.edu>2017-10-08 22:39:59 -0300
committerBenjamin J. Culkin <bjculkin@mix.wvu.edu>2017-10-08 22:39:59 -0300
commitc82e3b3b2de0633317ec8fc85925e91422820597 (patch)
tree96567416ce23c5ce85601f9cedc3a94bb1c55cba /BJC-Utils2/src/main/java/bjc/utils/funcdata/bst/BinarySearchTree.java
parentb3ac1c8690c3e14c879913e5dcc03a5f5e14876e (diff)
Start splitting into maven modules
Diffstat (limited to 'BJC-Utils2/src/main/java/bjc/utils/funcdata/bst/BinarySearchTree.java')
-rw-r--r--BJC-Utils2/src/main/java/bjc/utils/funcdata/bst/BinarySearchTree.java221
1 files changed, 0 insertions, 221 deletions
diff --git a/BJC-Utils2/src/main/java/bjc/utils/funcdata/bst/BinarySearchTree.java b/BJC-Utils2/src/main/java/bjc/utils/funcdata/bst/BinarySearchTree.java
deleted file mode 100644
index 8acd477..0000000
--- a/BJC-Utils2/src/main/java/bjc/utils/funcdata/bst/BinarySearchTree.java
+++ /dev/null
@@ -1,221 +0,0 @@
-package bjc.utils.funcdata.bst;
-
-import java.util.ArrayList;
-import java.util.Comparator;
-import java.util.List;
-import java.util.function.Predicate;
-
-import bjc.utils.funcdata.FunctionalList;
-import bjc.utils.funcdata.IList;
-
-/**
- * A binary search tree, with some mild support for functional traversal.
- *
- * @author ben
- *
- * @param <T>
- * The data type stored in the node.
- */
-public class BinarySearchTree<T> {
- /*
- * The comparator for use in ordering items
- */
- private final Comparator<T> comparator;
-
- /*
- * The current count of elements in the tree
- */
- private int elementCount;
-
- /*
- * The root element of the tree
- */
- private ITreePart<T> root;
-
- /**
- * Create a new tree using the specified way to compare elements.
- *
- * @param cmp
- * The thing to use for comparing elements
- */
- public BinarySearchTree(final Comparator<T> cmp) {
- if (cmp == null) throw new NullPointerException("Comparator must not be null");
-
- elementCount = 0;
- comparator = cmp;
- }
-
- /**
- * Add a node to the binary search tree.
- *
- * @param element
- * The data to add to the binary search tree.
- */
- public void addNode(final T element) {
- elementCount++;
-
- if (root == null) {
- root = new BinarySearchTreeNode<>(element, null, null);
- } else {
- root.add(element, comparator);
- }
- }
-
- /**
- * Check if an adjusted pivot falls with the bounds of a list
- *
- * @param elements
- * The list to get bounds from
- * @param pivot
- * The pivot
- * @param pivotAdjustment
- * The distance from the pivot
- * @return Whether the adjusted pivot is with the list
- */
- private boolean adjustedPivotInBounds(final IList<T> elements, final int pivot, final int pivotAdjustment) {
- return pivot - pivotAdjustment >= 0 && pivot + pivotAdjustment < elements.getSize();
- }
-
- /**
- * Balance the tree, and remove soft-deleted nodes for free.
- *
- * Takes O(N) time, but also O(N) space.
- */
- public void balance() {
- final IList<T> elements = new FunctionalList<>();
-
- // Add each element to the list in sorted order
- root.forEach(TreeLinearizationMethod.INORDER, element -> elements.add(element));
-
- // Clear the tree
- root = null;
-
- // Set up the pivot and adjustment for readding elements
- final int pivot = elements.getSize() / 2;
- int pivotAdjustment = 0;
-
- // Add elements until there aren't any left
- while (adjustedPivotInBounds(elements, pivot, pivotAdjustment)) {
- if (root == null) {
- // Create a new root element
- root = new BinarySearchTreeNode<>(elements.getByIndex(pivot), null, null);
- } else {
- // Add the left and right elements in a balanced
- // manner
- root.add(elements.getByIndex(pivot + pivotAdjustment), comparator);
-
- root.add(elements.getByIndex(pivot - pivotAdjustment), comparator);
- }
-
- // Increase the distance from the pivot
- pivotAdjustment++;
- }
-
- // Add any trailing unbalanced elements
- if (pivot - pivotAdjustment >= 0) {
- root.add(elements.getByIndex(pivot - pivotAdjustment), comparator);
- } else if (pivot + pivotAdjustment < elements.getSize()) {
- root.add(elements.getByIndex(pivot + pivotAdjustment), comparator);
- }
- }
-
- /**
- * Soft-delete a node from the tree.
- *
- * Soft-deleted nodes stay in the tree until trim()/balance() is
- * invoked, and are not included in traversals/finds.
- *
- * @param element
- * The node to delete
- */
- public void deleteNode(final T element) {
- elementCount--;
-
- root.delete(element, comparator);
- }
-
- /**
- * Get the root of the tree.
- *
- * @return The root of the tree.
- */
- public ITreePart<T> getRoot() {
- return root;
- }
-
- /**
- * Check if a node is in the tree
- *
- * @param element
- * The node to check the presence of for the tree.
- * @return Whether or not the node is in the tree.
- */
- public boolean isInTree(final T element) {
- return root.contains(element, comparator);
- }
-
- /**
- * Traverse the tree in a specified way until the function fails
- *
- * @param linearizationMethod
- * The way to linearize the tree for traversal
- * @param traversalPredicate
- * The function to use until it fails
- */
- public void traverse(final TreeLinearizationMethod linearizationMethod, final Predicate<T> traversalPredicate) {
- if (linearizationMethod == null)
- throw new NullPointerException("Linearization method must not be null");
- else if (traversalPredicate == null) throw new NullPointerException("Predicate must not be nulls");
-
- root.forEach(linearizationMethod, traversalPredicate);
- }
-
- /**
- * Remove all soft-deleted nodes from the tree.
- */
- public void trim() {
- final List<T> nodes = new ArrayList<>(elementCount);
-
- // Add all non-soft deleted nodes to the tree in insertion order
- traverse(TreeLinearizationMethod.PREORDER, node -> {
- nodes.add(node);
- return true;
- });
-
- // Clear the tree
- root = null;
-
- // Add the nodes to the tree in the order they were inserted
- nodes.forEach(node -> addNode(node));
- }
-
- @Override
- public String toString() {
- return String.format("BinarySearchTree [elementCount=%s, root='%s']", elementCount, root);
- }
-
- @Override
- public int hashCode() {
- final int prime = 31;
- int result = 1;
- result = prime * result + elementCount;
- result = prime * result + (root == null ? 0 : root.hashCode());
- return result;
- }
-
- @Override
- public boolean equals(final Object obj) {
- if (this == obj) return true;
- if (obj == null) return false;
- if (!(obj instanceof BinarySearchTree<?>)) return false;
-
- final BinarySearchTree<?> other = (BinarySearchTree<?>) obj;
-
- if (elementCount != other.elementCount) return false;
- if (root == null) {
- if (other.root != null) return false;
- } else if (!root.equals(other.root)) return false;
-
- return true;
- }
-}