二叉查找树（java版本）

package BinarySearch;public class BinarySearchTree {    private Node root = null;    public BinarySearchTree(int[] elements) {        if (elements != null && elements.length >= 1) {            for (int element : elements) {                insert(element);            }        }    }    public boolean delete(int value) {        return operation(value, false, true);    }    private void deleteNode(Node deleteNode) {        boolean isLeftNull = deleteNode.left == null;        boolean isRightNull = deleteNode.right == null;        if (isLeftNull && isRightNull) {            deleteNode = null;        } else if (isLeftNull) {//如果只有左子树为空，把右子树直接提上来就好了            Node rightNode = deleteNode.right;            deleteNode.value = deleteNode.right.value;            deleteNode.left = rightNode.left;            deleteNode.right = rightNode.right;        } else if (isRightNull) {//如果只有右子树为空，把左子树直接提上来就好了            Node leftNode = deleteNode.left;            deleteNode.value = deleteNode.left.value;            deleteNode.left = leftNode.left;            deleteNode.right = leftNode.right;        } else {            //如果左右都不为空的话，那么就找到 被删除节点的左节点的最右节点，            //将它顶替当前的被删除节点，然后将此最右节点的左子树放到 最右节点的父节点的右子树            Node tempLeftNode = deleteNode.left;            Node lastLeftTreeRightNode = tempLeftNode;            Node lastLeftTreeRightNodeParent = null;            while (lastLeftTreeRightNode.right != null) {                lastLeftTreeRightNodeParent = lastLeftTreeRightNode;                lastLeftTreeRightNode = lastLeftTreeRightNode.right;            }            deleteNode.value = lastLeftTreeRightNode.value;            if (lastLeftTreeRightNodeParent != null) {                lastLeftTreeRightNodeParent.right = lastLeftTreeRightNode.left;            }            lastLeftTreeRightNode = null;        }    }    public boolean search(int value) {        return !operation(value, false, false);    }    public boolean insert(int value) {        return operation(value, true, false);    }    private boolean operation(int value, boolean insert, boolean delete) {        if (root == null) {//根节点为空，直接new一个Node            if (insert) root = new Node(value);            else if (delete) return false;            return true;        }        Node tempRoot = root;        while (true) {            if (value == tempRoot.value) {//如果存在该元素的话，那么不用插入了                if (delete) {                    deleteNode(tempRoot);                    return true;                }                return false;            } else if (value > tempRoot.value) {                if (tempRoot.right == null) {                    if (insert) {                        tempRoot.right = new Node(value);                    } else if (delete) {                        return false;                    }                    return true;                }                tempRoot = tempRoot.right;            } else {                if (tempRoot.left == null) {                    if (insert) {                        tempRoot.left = new Node(value);                    } else if (delete) {                        return false;                    }                    return true;                }                tempRoot = tempRoot.left;            }        }    }    private static class Node {        private int value;        private Node left;        private Node right;        public Node(int value) {            this.value = value;        }    }}