package com.mjy.map;
import com.mjy.printer.BinaryTreeInfo;
import com.mjy.printer.BinaryTrees;
import java.util.LinkedList;
import java.util.Objects;
import java.util.Queue;
/**
* ***************************************************
*
* @ClassName HashMap
* @Description 描述
* @Author maojianyun
* @Date 2020/1/10 13:53
* @Version V1.0 ****************************************************
**/
@SuppressWarnings({ "unchecked", "unused" })
public class HashMap<K, V> implements Map<K, V> {
private final static boolean RED = false;
private final static boolean BLACK = true;
private Node<K, V>[] table;
private int size;
private static final int DEFAULT_CAPACITY = 1 << 4;
private static final float DEFAULT_LOAD_FACTOR = 0.75f;
public HashMap() {
table = new Node[DEFAULT_CAPACITY];
}
public int size() {
return size;
}
public boolean isEmpty() {
return size == 0;
}
public void clear() {
if (size == 0) {
return;
}
size = 0;
for (int i = 0; i < table.length; i++) {
table[i] = null;
}
}
public V put(K key, V value) {
resize();
int index = index(key);
// 取出index位置的红黑树根节点
Node<K, V> root = table[index];
if (root == null) {
root = new Node<K, V>(key, value, null);
table[index] = root;
size++;
// 修复红黑树性质
afterPut(root);
return null;
}
// 添加新的节点到红黑树上面
Node<K, V> parent = root;
Node<K, V> node = root;
int cmp = 0;
K k1 = key;
int h1 = k1 == null ? 0 : k1.hashCode();
Node<K, V> result = null;
boolean searched = false; // 是否已经搜索过这个key
do {
parent = node;
K k2 = node.key;
int h2 = node.hash;
if (h1 > h2) {
cmp = 1;
} else if (h1 < h2) {
cmp = -1;
} else if (Objects.equals(k1, k2)) {
cmp = 0;
} else if (k1 != null && k2 != null
&& k1.getClass() == k2.getClass()
&& k1 instanceof Comparable
&& (cmp = ((Comparable<K>) k1).compareTo(k2)) != 0) {
} else if (searched) { // 已经扫描了
cmp = System.identityHashCode(k1) - System.identityHashCode(k2);
} else {
if ((node.left != null && (result = node(node.left, k1)) != null)
|| (node.right != null && (result = node(node.right, k1)) != null)) {
// 已经存在这个key
node = result;
cmp = 0;
} else { // 不存在这个key
searched = true;
cmp = System.identityHashCode(k1) - System.identityHashCode(k2);
}
}
if (cmp > 0) {
node = node.right;
} else if (cmp < 0) {
node = node.left;
} else { // 相等
V oldValue = node.value;
node.key = key;
node.value = value;
node.hash = h1;
return oldValue;
}
} while (node != null);
Node<K, V> newNode = new Node<K, V>(key, value, parent);
if (cmp > 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 (size == 0) {
return false;
}
for (int i = 0; i < table.length; i++) {
if (table[i] == null) {
continue;
}
Queue<Node<K, V>> queue = new LinkedList<>();
queue.offer(table[i]);
while (!queue.isEmpty()) {
Node<K, V> node = queue.poll();
if (Objects.equals(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 (size == 0 || visitor.stop) {
return;
}
Queue<Node<K, V>> queue = new LinkedList<>();
for (int i = 0; i < table.length; i++) {
if (table[i] == null) {
continue;
}
queue.offer(table[i]);
while (!queue.isEmpty()) {
Node<K, V> node = queue.poll();
visitor.stop = visitor.visit(node.key, node.value);
if (node.left != null) {
queue.offer(node.left);
}
if (node.right != null) {
queue.offer(node.right);
}
}
}
}
/**
* 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;
node.hash = su.hash;
// 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<K, V> replacement = node.left != null ? node.left : node.right;
int index = index(node);
if (replacement != null) { // 删除度为1的节点
replacement.parent = node.parent;
if (node.parent == null) {
table[index] = 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
table[index] = 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;
}
private void resize() {
// 装填因子 <= 0.75
if (size / table.length <= DEFAULT_LOAD_FACTOR) {
return;
}
Node<K, V> [] oldTable = table;
table = new Node[oldTable.length << 1];
Queue<Node<K, V>> queue = new LinkedList<Node<K,V>>();
for(int i = 0; i < oldTable.length; i++) {
if (oldTable[i] == null) {
continue;
}
queue.offer(oldTable[i]);
while(!queue.isEmpty()) {
Node<K, V> node = queue.poll();
if (node.left != null) {
queue.offer(node.left);
}
if (node.right != null) {
queue.offer(node.right);
}
// 挪动代码得放到最后面
moveNode(node);
}
}
}
private void moveNode(Node<K, V> newNode) {
// 重置
newNode.parent = null;
newNode.left = null;
newNode.right = null;
newNode.color = RED;
int index = index(newNode);
// 取出index位置的红黑树根节点
Node<K, V> root = table[index];
if (root == null) {
root = newNode;
table[index] = root;
afterPut(root);
return;
}
// 添加新的节点到红黑树上面
Node<K, V> parent = root;
Node<K, V> node = root;
int cmp = 0;
K k1 = newNode.key;
int h1 = newNode.hash;
do {
parent = node;
K k2 = node.key;
int h2 = node.hash;
if (h1 > h2) {
cmp = 1;
} else if (h1 < h2) {
cmp = -1;
} else if (k1 != null && k2 != null
&& k1 instanceof Comparable
&& k1.getClass() == k2.getClass()
&& (cmp = ((Comparable<K>)k1).compareTo(k2)) != 0) {
} else {
cmp = System.identityHashCode(k1) - System.identityHashCode(k2);
}
if (cmp > 0) {
node = node.right;
} else if (cmp < 0) {
node = node.left;
}
} while (node != null);
// 看看插入到父节点的哪个位置
newNode.parent = parent;
if (cmp > 0) {
parent.right = newNode;
} else {
parent.left = newNode;
}
// 新添加节点之后的处理
afterPut(newNode);
}
/**
* 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;
}
private Node<K, V> node(K key) {
Node<K, V> root = table[index(key)];
return root == null ? null : node(root, key);
}
private Node<K, V> node(Node<K, V> node, K k1) {
int h1 = k1 == null ? 0 : k1.hashCode();
// 存储查找结果
Node<K, V> result = null;
int cmp = 0;
while (node != null) {
K k2 = node.key;
int h2 = node.hash;
// 先比较哈希值
if (h1 > h2) {
node = node.right;
} else if (h1 < h2) {
node = node.left;
} else if (Objects.equals(k1, k2)) {
return node;
} else if (k1 != null && k2 != null
&& k1.getClass() == k2.getClass()
&& k1 instanceof Comparable
&& (cmp = ((Comparable<K>) k1).compareTo(k2)) != 0) {
node = cmp > 0 ? node.right : node.left;
} else if (node.right != null && (result = node(node.right, k1)) != null) {
return result;
} else { // 只能往左边找
node = node.left;
}
}
return null;
}
/**
* 得到hash索引（在数组中的索引下标）
*
* @param key
* @return
*/
private int index(K key) {
if (key == null) {
return 0;
}
int hash = key.hashCode();
hash = hash ^ (hash >>> 16);
return hash & (table.length - 1);
}
private int index(Node<K, V> node) {
if (node == null) {
return 0;
}
int hash = node.hash;
hash = hash ^ (hash >>> 16);
return hash & (table.length - 1);
}
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);
}
}
}
/**
* 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 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
table[index(grand.key)] = 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;
int hash;
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.hash = key == null ? 0 : key.hashCode();
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() {
return color + "_Node_" + key + "_" + value;
}
}
public void print() {
if (size == 0)
return;
for (int i = 0; i < table.length; i++) {
final Node<K, V> root = table[i];
System.out.println("【index = " + i + "】");
BinaryTrees.println(new BinaryTreeInfo() {
@Override
public Object string(Object node) {
return node;
}
@Override
public Object root() {
return root;
}
@Override
public Object right(Object node) {
return ((Node<K, V>) node).right;
}
@Override
public Object left(Object node) {
return ((Node<K, V>) node).left;
}
});
System.out.println("---------------------------------------------------");
}
}
}
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