基于数组+链表简单实现HashMap

布满荆棘的人生 2024-03-26 09:09 55阅读 0赞

数组+链表实现HashMap，可往HashMap中存null值。

public class SevenHashMap<K,V> {
        
        private Entry[] entries = new Entry[10000];
        /**
         * 数组+链表实现
         * @param <K>
         * @param <V>
         */
        class Entry<K,V>{
        
            K k;
            V v;
            Entry<K,V> next;
    
            public Entry(K k, V v) {
        
                this.k = k;
                this.v = v;
            }
        }
    
        public void put(K k,V v){
        
            //数组+链表实现 hash算法
            int index = k.hashCode() % entries.length;
            //判断key是否发生了冲突
            Entry oldEntry = entries[index];
            if (oldEntry == null){
        
                //key 没有发生hash碰撞问题
                entries[index] = new Entry<K,V>(k,v);
            }else {
        
                oldEntry.next = new Entry<K,V>(k,v);
            }
    
        }
    
        public V get(K k){
        
            int index = k.hashCode() % entries.length;
            for (Entry oldEntry = entries[index];oldEntry != null;oldEntry=oldEntry.next){
        
                if (oldEntry.k.equals(k)){
        
                    return (V) oldEntry.v;
                }
            }
            return null;
        }
    
        public static void main(String[] args) {
        
            SevenHashMap<Object, String> hashMap = new SevenHashMap<>();
            hashMap.put(1,"lisi");
            hashMap.put(2,"zhangsan");
            System.out.println(hashMap.get(1));
        }
    
    
    }

![在这里插入图片描述][6b90ceccf4ad46afbdbe9c2f032400c1.png]

[6b90ceccf4ad46afbdbe9c2f032400c1.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/57ae0b1bdfd04f349916195947f5376a.png