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Add the codes of hashmap (#553)

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of chaining and open addressing
This commit is contained in:
Yudong Jin
2023-06-14 02:01:06 +08:00
committed by GitHub
parent d3e597af94
commit 9563965a20
27 changed files with 1280 additions and 207 deletions
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30
codes/java/chapter_hashing/array_hash_map.java
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@ -8,12 +8,12 @@ package chapter_hashing;
import java.util.*;
/* 键值对 int->String */
class Entry {
/* 键值对 */
class Pair {
public int key;
public String val;
public Entry(int key, String val) {
public Pair(int key, String val) {
this.key = key;
this.val = val;
}
@ -21,7 +21,7 @@ class Entry {
/* 基于数组简易实现的哈希表 */
class ArrayHashMap {
private List<Entry> buckets;
private List<Pair> buckets;
public ArrayHashMap() {
// 初始化数组，包含 100 个桶
@ -40,7 +40,7 @@ class ArrayHashMap {
/* 查询操作 */
public String get(int key) {
int index = hashFunc(key);
Entry pair = buckets.get(index);
Pair pair = buckets.get(index);
if (pair == null)
return null;
return pair.val;
@ -48,7 +48,7 @@ class ArrayHashMap {
/* 添加操作 */
public void put(int key, String val) {
Entry pair = new Entry(key, val);
Pair pair = new Pair(key, val);
int index = hashFunc(key);
buckets.set(index, pair);
}
@ -61,19 +61,19 @@ class ArrayHashMap {
}
/* 获取所有键值对 */
public List<Entry> entrySet() {
List<Entry> entrySet = new ArrayList<>();
for (Entry pair : buckets) {
public List<Pair> pairSet() {
List<Pair> pairSet = new ArrayList<>();
for (Pair pair : buckets) {
if (pair != null)
entrySet.add(pair);
pairSet.add(pair);
}
return entrySet;
return pairSet;
}
/* 获取所有键 */
public List<Integer> keySet() {
List<Integer> keySet = new ArrayList<>();
for (Entry pair : buckets) {
for (Pair pair : buckets) {
if (pair != null)
keySet.add(pair.key);
}
@ -83,7 +83,7 @@ class ArrayHashMap {
/* 获取所有值 */
public List<String> valueSet() {
List<String> valueSet = new ArrayList<>();
for (Entry pair : buckets) {
for (Pair pair : buckets) {
if (pair != null)
valueSet.add(pair.val);
}
@ -92,7 +92,7 @@ class ArrayHashMap {
/* 打印哈希表 */
public void print() {
for (Entry kv : entrySet()) {
for (Pair kv : pairSet()) {
System.out.println(kv.key + " -> " + kv.val);
}
}
@ -126,7 +126,7 @@ public class array_hash_map {
/* 遍历哈希表 */
System.out.println("\n遍历键值对 Key->Value");
for (Entry kv : map.entrySet()) {
for (Pair kv : map.pairSet()) {
System.out.println(kv.key + " -> " + kv.val);
}
System.out.println("\n单独遍历键 Key");