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;
        }
    }

}