mirror of
https://github.com/krahets/hello-algo.git
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e720aa2d24
* Sync recent changes to the revised Word. * Revised the preface chapter * Revised the introduction chapter * Revised the computation complexity chapter * Revised the chapter data structure * Revised the chapter array and linked list * Revised the chapter stack and queue * Revised the chapter hashing * Revised the chapter tree * Revised the chapter heap * Revised the chapter graph * Revised the chapter searching * Reivised the sorting chapter * Revised the divide and conquer chapter * Revised the chapter backtacking * Revised the DP chapter * Revised the greedy chapter * Revised the appendix chapter * Revised the preface chapter doubly * Revised the figures
134 lines
3.4 KiB
C#
134 lines
3.4 KiB
C#
/**
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* File: array_hash_map.cs
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* Created Time: 2022-12-23
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* Author: haptear (haptear@hotmail.com)
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*/
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namespace hello_algo.chapter_hashing;
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/* 键值对 int->string */
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class Pair(int key, string val) {
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public int key = key;
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public string val = val;
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}
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/* 基于数组实现的哈希表 */
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class ArrayHashMap {
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List<Pair?> buckets;
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public ArrayHashMap() {
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// 初始化数组，包含 100 个桶
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buckets = [];
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for (int i = 0; i < 100; i++) {
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buckets.Add(null);
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}
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}
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/* 哈希函数 */
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int HashFunc(int key) {
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int index = key % 100;
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return index;
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}
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/* 查询操作 */
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public string? Get(int key) {
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int index = HashFunc(key);
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Pair? pair = buckets[index];
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if (pair == null) return null;
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return pair.val;
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}
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/* 添加操作 */
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public void Put(int key, string val) {
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Pair pair = new(key, val);
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int index = HashFunc(key);
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buckets[index] = pair;
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}
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/* 删除操作 */
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public void Remove(int key) {
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int index = HashFunc(key);
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// 置为 null ，代表删除
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buckets[index] = null;
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}
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/* 获取所有键值对 */
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public List<Pair> PairSet() {
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List<Pair> pairSet = [];
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foreach (Pair? pair in buckets) {
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if (pair != null)
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pairSet.Add(pair);
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}
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return pairSet;
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}
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/* 获取所有键 */
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public List<int> KeySet() {
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List<int> keySet = [];
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foreach (Pair? pair in buckets) {
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if (pair != null)
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keySet.Add(pair.key);
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}
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return keySet;
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}
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/* 获取所有值 */
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public List<string> ValueSet() {
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List<string> valueSet = [];
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foreach (Pair? pair in buckets) {
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if (pair != null)
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valueSet.Add(pair.val);
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}
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return valueSet;
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}
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/* 打印哈希表 */
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public void Print() {
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foreach (Pair kv in PairSet()) {
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Console.WriteLine(kv.key + " -> " + kv.val);
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}
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}
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}
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public class array_hash_map {
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[Test]
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public void Test() {
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/* 初始化哈希表 */
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ArrayHashMap map = new();
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/* 添加操作 */
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// 在哈希表中添加键值对 (key, value)
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map.Put(12836, "小哈");
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map.Put(15937, "小啰");
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map.Put(16750, "小算");
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map.Put(13276, "小法");
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map.Put(10583, "小鸭");
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Console.WriteLine("\n添加完成后，哈希表为\nKey -> Value");
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map.Print();
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/* 查询操作 */
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// 向哈希表输入键 key ，得到值 value
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string? name = map.Get(15937);
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Console.WriteLine("\n输入学号 15937 ，查询到姓名 " + name);
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/* 删除操作 */
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// 在哈希表中删除键值对 (key, value)
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map.Remove(10583);
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Console.WriteLine("\n删除 10583 后，哈希表为\nKey -> Value");
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map.Print();
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/* 遍历哈希表 */
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Console.WriteLine("\n遍历键值对 Key->Value");
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foreach (Pair kv in map.PairSet()) {
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Console.WriteLine(kv.key + " -> " + kv.val);
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}
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Console.WriteLine("\n单独遍历键 Key");
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foreach (int key in map.KeySet()) {
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Console.WriteLine(key);
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}
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Console.WriteLine("\n单独遍历值 Value");
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foreach (string val in map.ValueSet()) {
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Console.WriteLine(val);
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}
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}
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}
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