package com.mjy.map;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Stack;
/**
* ***************************************************
* @ClassName TreeMap
* @Description 描述
* @Author maojianyun
* @Date 2020/1/9 22:06
* @Version V1.0
* ****************************************************
**/
public class TreeMap<K, V> implements Map<K, V>{
private final static boolean RED = false;
private final static boolean BLACK = true;
private Node<K, V> root;
private int size;
private Comparator<K> comparator;
public TreeMap() {
this(null);
}
public TreeMap(Comparator<K> comparator) {
this.comparator = comparator;
}
public int size() {
return size;
}
public boolean isEmpty() {
return size == 0;
}
public void clear() {
root = null;
}
public V put(K key, V value) {
keyNotNullCheck(key);
if (root == null) { // 添加根节点
Node<K, V> node = new Node<K, V>(key, value, null);
root = node;
size++;
afterPut(node);
return null;
}
Node<K, V> temp = root;
Node<K, V> parent = root;
int com = 0;
while (temp != null){
parent = temp;
com = compare(key, temp.key);
if (com > 0) {
temp = temp.right;
} else if (com < 0){
temp = temp.left;
} else { // 相等、覆盖原来的值并且返回
temp.key = key;
V oldValue = temp.value;
temp.value = value;
return oldValue;
}
}
Node<K, V> newNode = new Node<K, V>(key, value, parent);
if (com > 0) {
parent.right = newNode;
} else {
parent.left = newNode;
}
size++;
afterPut(newNode);
return null;
}
public V get(K key) {
Node<K, V> node = node(key);
return node != null? node.value: null;
}
public V remove(K key) {
return remove(node(key));
}
public boolean containsKey(K key) {
return node(key) != null;
}
public boolean containsValue(V value) {
if (value == null) {
return false;
}
Queue<Node<K, V>> queue = new LinkedList<Node<K, V>>();
queue.offer(root);
while(queue.size() > 0){
Node<K, V> node = queue.poll();
// 比较值
if (valEquals(value, node.value)) {
return true;
}
if (node.left != null) {
queue.offer(node.left);
}
if (node.right != null) {
queue.offer(node.right);
}
}
return false;
}
public void traversal(Visitor<K, V> visitor) {
if (root == null) {
return;
}
Node<K, V> temp = root;
Stack<Node<K, V>> stack = new Stack<Node<K, V>>();
while (temp != null || !stack.isEmpty()) {
if (temp != null) {
stack.push(temp);
temp = temp.left;
} else {
if (visitor.stop) {
break;
}
Node<K, V> node = stack.pop();
visitor.stop = visitor.visit(node.key, node.value);
temp = node.right;
}
}
}
private boolean valEquals(V v1, V v2) {
return v1 == null ? v2 == null : v1.equals(v2);
}
/**
* 删除node
* @param node
* @return
*/
private V remove(Node<K, V> node){
if (node == null) {
return null;
}
V oldValue = node.value;
if (node.hasTwoChildren()){ // 度为2的节点
// 找到后继节点
Node<K, V> su = successor(node);
// 用后继节点的值覆盖度为2的节点的值
node.key = su.key;
node.value = su.value;
// 删除后继节点
node = su;
}
// 删除node节点（node的度必然是1或者0）
// 如果度为1、则返回的是其子节点
Node replacement = node.left != null? node.left: node.right;
if (replacement != null) { // 删除度为1的节点
replacement.parent = node.parent;
if (node.parent == null) {
root = replacement;
}else if (node.isLeftChild()) {
node.parent.left = replacement;
} if (node.isRightChild()) {
node.parent.right = replacement;
}
// 删除节点之后的处理
afterRemove(replacement);
} else if (node.parent == null) { // node是叶子节点并且是根节点
root = null;
} else { // node是叶子节点，但不是根节点
if (node == node.parent.left) {
node.parent.left = null;
} else { // node == node.parent.right
node.parent.right = null;
}
// 删除节点之后的处理
afterRemove(node);
}
size--;
return oldValue;
}
/**
* 根据可以得到node
* @param key
* @return
*/
private Node<K, V> node(K key) {
keyNotNullCheck(key);
Node<K, V> temp = root;
while (temp != null) {
int com = compare(key, temp.key);
if (com == 0) {
return temp;
} else if (com > 0) {
temp = temp.right;
} else {
temp = temp.left;
}
}
return null;
}
/**
* 得到节点的后继节点
* @param node
* @return
*/
private Node<K, V> successor(Node<K, V> node){
if (node == null) return null;
// 前驱节点在左子树当中（right.left.left.left....）
Node<K, V> p = node.right;
if (p != null) {
while (p.left != null) {
p = p.left;
}
return p;
}
// 从父节点、祖父节点中寻找前驱节点
while (node.parent != null && node == node.parent.right) {
node = node.parent;
}
return node.parent;
}
/**
* key的比较：返回值大于0说明key1 > key2, 返回值等于0说明key1 == key2 ,返回值小于0说key1 < key2
* @param key1
* @param key2
* @return
*/
private int compare(K key1, K key2){
if (comparator != null) {
return comparator.compare(key1, key2);
}
return ((Comparable)key1).compareTo(key2);
}
/**
* 校验可以是否为空
* @param key
*/
private void keyNotNullCheck(K key){
if (key == null) {
throw new IllegalArgumentException("key must not be null");
}
}
/**
* 给指定节点染指定的颜色
* @param node 节点
* @param color 颜色
* @return 节点
*/
private Node<K, V> color(Node<K, V> node, boolean color) {
if (node != null) {
node.color = color;
}
return node;
}
/**
* 节点染成红色
* @param node
* @return
*/
private Node<K, V> red(Node<K, V> node){
return color(node, RED);
}
/**
* 节点染成黑色
* @param node
* @return
*/
private Node<K, V> black(Node<K, V> node){
return color(node, BLACK);
}
/**
* 得到节点的颜色
* @param node
* @return
*/
private boolean colorOf(Node<K, V> node){
return node == null? BLACK: node.color;
}
/**
* 是否是黑色
* @param node
* @return
*/
private boolean isBlack(Node<K, V> node) {
return colorOf(node) == BLACK;
}
/**
* 是否是红色
* @param node
* @return
*/
private boolean isRed(Node<K, V> node) {
return colorOf(node) == RED;
}
private void afterPut(Node<K, V> node) {
Node<K, V> parent = node.parent;
// 添加的是根节点 或者 上溢到达了根节点
if (parent == null) {
black(node);
return;
}
// 如果父节点是黑色，直接返回
if (isBlack(parent)) {
return;
}
// 叔父节点
Node<K, V> uncle = parent.sibling();
// 祖父节点
Node<K, V> grand = red(parent.parent);
if (isRed(uncle)) { // 叔父节点是红色【B树节点上溢】
black(parent);
black(uncle);
// 把祖父节点当做是新添加的节点
afterPut(grand);
return;
}
// 叔父节点不是红色
if (parent.isLeftChild()) { // L
if (node.isLeftChild()) { // LL
black(parent);
} else { // LR
black(node);
rotateLeft(parent);
}
rotateRight(grand);
} else { // R
if (node.isLeftChild()) { // RL
black(node);
rotateRight(parent);
} else { // RR
black(parent);
}
rotateLeft(grand);
}
}
private void afterRemove(Node<K, V> node) {
// 如果删除的节点是红色
// 或者 用以取代删除节点的子节点是红色
if (isRed(node)) {
black(node);
return;
}
Node<K, V> parent = node.parent;
if (parent == null) {
return;
}
// 删除的是黑色叶子节点【下溢】
// 判断被删除的node是左还是右
boolean left = parent.left == null || node.isLeftChild();
Node<K, V> sibling = left ? parent.right : parent.left;
if (left) { // 被删除的节点在左边，兄弟节点在右边
if (isRed(sibling)) { // 兄弟节点是红色
black(sibling);
red(parent);
rotateLeft(parent);
// 更换兄弟
sibling = parent.right;
}
// 兄弟节点必然是黑色
if (isBlack(sibling.left) && isBlack(sibling.right)) {
// 兄弟节点没有1个红色子节点，父节点要向下跟兄弟节点合并
boolean parentBlack = isBlack(parent);
black(parent);
red(sibling);
if (parentBlack) {
afterRemove(parent);
}
} else { // 兄弟节点至少有1个红色子节点，向兄弟节点借元素
// 兄弟节点的左边是黑色，兄弟要先旋转
if (isBlack(sibling.right)) {
rotateRight(sibling);
sibling = parent.right;
}
color(sibling, colorOf(parent));
black(sibling.right);
black(parent);
rotateLeft(parent);
}
} else { // 被删除的节点在右边，兄弟节点在左边
if (isRed(sibling)) { // 兄弟节点是红色
black(sibling);
red(parent);
rotateRight(parent);
// 更换兄弟
sibling = parent.left;
}
// 兄弟节点必然是黑色
if (isBlack(sibling.left) && isBlack(sibling.right)) {
// 兄弟节点没有1个红色子节点，父节点要向下跟兄弟节点合并
boolean parentBlack = isBlack(parent);
black(parent);
red(sibling);
if (parentBlack) {
afterRemove(parent);
}
} else { // 兄弟节点至少有1个红色子节点，向兄弟节点借元素
// 兄弟节点的左边是黑色，兄弟要先旋转
if (isBlack(sibling.left)) {
rotateLeft(sibling);
sibling = parent.left;
}
color(sibling, colorOf(parent));
black(sibling.left);
black(parent);
rotateRight(parent);
}
}
}
private void rotateLeft(Node<K, V> grand) {
Node<K, V> parent = grand.right;
Node<K, V> child = parent.left;
grand.right = child;
parent.left = grand;
afterRotate(grand, parent, child);
}
private void rotateRight(Node<K, V> grand) {
Node<K, V> parent = grand.left;
Node<K, V> child = parent.right;
grand.left = child;
parent.right = grand;
afterRotate(grand, parent, child);
}
private void afterRotate(Node<K, V> grand, Node<K, V> parent, Node<K, V> child) {
// 让parent称为子树的根节点
parent.parent = grand.parent;
if (grand.isLeftChild()) {
grand.parent.left = parent;
} else if (grand.isRightChild()) {
grand.parent.right = parent;
} else { // grand是root节点
root = parent;
}
// 更新child的parent
if (child != null) {
child.parent = grand;
}
// 更新grand的parent
grand.parent = parent;
}
/**
* ***************************************************
* @ClassName Node<K, V>
* @Description 红黑树节点
* @Author maojianyun
* @Date 2020/1/9 22:06
* @Version V1.0
* ****************************************************
**/
private static class Node<K, V>{
// 默认为红色
boolean color = RED;
K key;
V value;
Node<K, V> left;
Node<K, V> right;
Node<K, V> parent;
public Node(K key, V value, Node<K, V> parent){
this.key = key;
this.value = value;
this.parent = parent;
}
/**
* 是否是叶子节点
* @return
*/
public boolean isLeaf(){
return left == null && right == null;
}
/**
* 是否有两个孩子
* @return
*/
public boolean hasTwoChildren(){
return left != null && right != null;
}
/**
* 是否是左孩子
* @return
*/
public boolean isLeftChild(){
return parent != null && this == parent.left;
}
/**
* 是否是右孩子
* @return
*/
public boolean isRightChild(){
return parent != null && this == parent.right;
}
/**
* 得到兄弟节点
* @return
*/
public Node<K, V> sibling() {
if (isLeftChild()) {
return parent.right;
}
if (isRightChild()) {
return parent.left;
}
return null;
}
@Override
public String toString() {
String str = "";
if (color == RED) {
str = "R_";
}
return str + key.toString() + "_" + value.toString();
}
}
}
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