集合及映射

Author: tianqing.liang

11-Set/BST.dart renamed to 11-Set-And-Map/BST.dart

@@ -0,0 +1,166 @@
+import 'Map.dart';
+
+/**
+ * 二分搜索树映射
+ */
+class BSTMap<K extends Comparable<K>, V> extends Map<K, V> {
+  _Node? root;
+
+  int? size;
+
+  BSTMap() {
+    root = null;
+    size = 0;
+  }
+
+  @override
+  add(key, value) {
+    // TODO: implement add
+    root = _addNode(root!, key, value);
+  }
+
+  _Node _addNode(_Node node, K key, V value) {
+    if (node == null) {
+      size = size! + 1;
+      return _Node(key, value);
+    }
+
+    if (key.compareTo(node.key) < 0) {
+      node.left = _addNode(node.left!, key, value);
+    } else if (key.compareTo(node.key) > 0) {
+      node.right = _addNode(node.right!, key, value);
+    } else {
+      // key.compareTo(node.key) == 0
+      node.value = value;
+    }
+    return node;
+  }
+
+  _Node? _getNode(_Node? node, K key) {
+    if (node == null) return null;
+
+    if (key.compareTo(node.key) == 0) {
+      return node;
+    } else if (key.compareTo(node.key) < 0) {
+      return _getNode(node.left, key);
+    } else {
+      // if(key.compareTo(node.key) > 0)
+      return _getNode(node.right, key);
+    }
+  }
+
+  @override
+  bool contains(key) {
+    return _getNode(root, key) != null;
+  }
+
+  @override
+  get(key) {
+    _Node? node = _getNode(root, key);
+    return node == null ? null : node.value;
+  }
+
+  @override
+  int? getSize() {
+    return size;
+  }
+
+  @override
+  bool isEmpty() {
+    return size == 0;
+  }
+
+  @override
+  remove(key) {
+    _Node? node = _getNode(root, key);
+    if(node != null){
+      root = _removeNode(root!, key);
+      return node.value;
+    }
+    return null;
+  }
+
+  _Node? _removeNode(_Node node, K key){
+
+    if( node == null ){
+      return null;
+    }
+    if( key.compareTo(node.key) < 0 ){
+      node.left = _removeNode(node.left! , key);
+      return node;
+    }
+    else if(key.compareTo(node.key) > 0 ){
+      node.right = _removeNode(node.right!, key);
+      return node;
+    }
+    else{
+      // 待删除节点左子树为空的情况
+      if(node.left == null){
+        _Node? rightNode = node.right;
+        node.right = null;
+        size = size! -1;
+        return rightNode;
+      }
+      // 待删除节点右子树为空的情况
+      if(node.right == null){
+        _Node? leftNode = node.left;
+        node.left = null;
+        size = size! - 1;
+        return leftNode;
+      }
+      // 待删除节点左右子树均不为空的情况
+      // 找到比待删除节点大的最小节点, 即待删除节点右子树的最小节点
+      // 用这个节点顶替待删除节点的位置
+      _Node successor = _minimum(node.right!);
+      successor.right = _removeMin(node.right!);
+      successor.left = node.left;
+      node.left = node.right = null;
+      return successor;
+    }
+  }
+
+  // 删除掉以node为根的二分搜索树中的最小节点
+  // 返回删除节点后新的二分搜索树的根
+  _Node _removeMin(_Node node){
+    if(node.left == null){
+      _Node? rightNode = node.right;
+      node.right = null;
+      size = size! -1;
+      return rightNode!;
+    }
+    node.left = _removeMin(node.left!);
+    return node;
+  }
+
+  // 返回以node为根的二分搜索树的最小值所在的节点
+  _Node _minimum(_Node node){
+    if(node.left == null){
+      return node;
+    }
+    return _minimum(node.left!);
+  }
+
+  @override
+  set(key, newValue) {
+    _Node? node = _getNode(root, key);
+    if(node == null){
+      throw new Exception(" $key + doesn't exist!");
+    }
+    node.value = newValue;
+  }
+}
+
+class _Node<K, V> {
+  K? key;
+
+  V? value;
+
+  _Node? left, right;
+
+  _Node(K key, V value) {
+    this.key = key;
+    this.value = value;
+    left = null;
+    right = null;
+  }
+}

11-Set-And-Map/BSTMap.dart

@@ -1,7 +1,9 @@
 import 'Set.dart';
 import 'BST.dart';
 
-
+/**
+ * 二分搜索树集合
+ */
 class BSTSet<T extends Comparable<T>> extends Set<T>{
 
   BST? bst;

11-Set/BSTSet.dart renamed to 11-Set-And-Map/BSTSet.dart

@@ -1,6 +1,9 @@
 import 'dart:io';
 import 'dart:convert';
 
+/**
+ * 文件操作类
+ */
 class FileOperator{
 
     static Future<List> getFileString(String filename) async{

11-Set/FileOperator.dart renamed to 11-Set-And-Map/FileOperator.dart

@@ -0,0 +1,111 @@
+import 'Map.dart';
+
+/**
+ * 链表映射
+ */
+class LinkedListMap<K ,V> extends Map<K ,V>{
+
+  _Node? dummyHead;
+  int? size;
+
+  @override
+  add(key, value) {
+    _Node? node = _getNode(key);
+    if(node == null){
+      dummyHead!.next = _Node(key, value, dummyHead!.next);
+      size = size! + 1;
+    }
+    else{
+      node.value = value;
+    }
+  }
+
+  LinkedListMap(){
+    dummyHead =_Node.withEmty();
+    size = 0;
+  }
+
+  @override
+  bool contains(key) {
+    return _getNode(key) != null;
+  }
+
+  @override
+  get(key) {
+    _Node? node = _getNode(key);
+    return node == null ? null : node.value;
+  }
+
+  @override
+  int? getSize() {
+    return size;
+  }
+
+  @override
+  bool isEmpty() {
+    return size == 0;
+  }
+
+  @override
+  V? remove(K key) {
+    _Node prev = dummyHead!;
+    while(prev.next != null){
+      if(prev.next!.key.equals(key))
+        break;
+      prev = prev.next!;
+    }
+
+    if(prev.next != null){
+      _Node delNode = prev.next!;
+      prev.next = delNode.next;
+      delNode.next = null;
+      size = size! -1;
+      return delNode.value;
+    }
+
+    return null;
+  }
+
+  @override
+  set(K key, newValue) {
+    _Node? node = _getNode(key);
+    if(node == null){
+      throw new Exception("${key} doesn't exist!");
+    }
+    node.value = newValue;
+  }
+
+  _Node? _getNode(K key){
+    _Node? cur = dummyHead!.next;
+    while(cur != null){
+      if(cur.key.equals(key))
+        return cur;
+      cur = cur.next;
+    }
+    return null;
+  }
+
+}
+class _Node<K ,V >{
+  K? key;
+  V? value;
+  _Node? next;
+
+  _Node(this.key, this.value, this.next);
+
+  _Node.withEmptyHead(K key, V value){
+    _Node(key, value, null);
+  }
+
+  _Node.withEmty(){
+    _Node(null, null, null);
+  }
+  @override
+  String toString() {
+    // TODO: implement toString
+    StringBuffer res =new StringBuffer();
+    res.write("${key.toString()} : ${value.toString()}");
+    return res.toString();
+  }
+}
+

11-Set/LinkedList.dart renamed to 11-Set-And-Map/LinkedList.dart

@@ -1,6 +1,9 @@
 import 'Stack.dart';
 import 'LinkedList.dart';
 
+/**
+ * 链表栈
+ */
 class LinkedListStack implements Stack{
 
   LinkedList? _linkedList;

11-Set-And-Map/LinkedListMap.dart

@@ -0,0 +1,9 @@
+abstract class Map<K,V>{
+  add(K key, V value);
+  V? remove(K key);
+  bool contains(K key);
+  V get(K key);
+  set(K key, V newValue);
+  int? getSize();
+  bool isEmpty();
+}

11-Set/LinkedListQueue.dart renamed to 11-Set-And-Map/LinkedListQueue.dart

@@ -12,7 +12,7 @@
 8. 快速排序,快速排序优化，二路快排，三路快排
 9. 二分搜索,二分搜索优化
 10. 二分搜索树,二分搜索树搜索、移除最大最小值
-11. 集合,使用二分搜索树构建集合
+11. 集合 和 映射
 
 #### SDK版本
 1. 版本：2.12.3