Custom HashMap Implementation.java

import java.util.LinkedList;

class MyHashMap<K, V> {
    private static class Entry<K, V> {
        K key;
        V value;

        Entry(K key, V value) {
            this.key = key;
            this.value = value;
        }
    }

    private LinkedList<Entry<K, V>>[] table;
    private int size;
    private static final int INITIAL_CAPACITY = 16;
    private static final float LOAD_FACTOR = 0.75f;

    @SuppressWarnings("unchecked")
    public MyHashMap() {
        table = new LinkedList[INITIAL_CAPACITY];
        for (int i = 0; i < INITIAL_CAPACITY; i++) {
            table[i] = new LinkedList<>();
        }
        size = 0;
    }

    private int getIndex(K key) {
        return key == null ? 0 : Math.abs(key.hashCode() % table.length);
    }

    public void put(K key, V value) {
        int index = getIndex(key);
        LinkedList<Entry<K, V>> bucket = table[index];

        for (Entry<K, V> entry : bucket) {
            if (entry.key.equals(key)) {
                entry.value = value; // Replace existing value
                return;
            }
        }

        bucket.add(new Entry<>(key, value));
        size++;

        if ((float) size / table.length > LOAD_FACTOR) {
            resize();
        }
    }

    public V get(K key) {
        int index = getIndex(key);
        LinkedList<Entry<K, V>> bucket = table[index];

        for (Entry<K, V> entry : bucket) {
            if (entry.key.equals(key)) {
                return entry.value;
            }
        }

        return null; // Not found
    }

    public void remove(K key) {
        int index = getIndex(key);
        LinkedList<Entry<K, V>> bucket = table[index];

        for (Entry<K, V> entry : bucket) {
            if (entry.key.equals(key)) {
                bucket.remove(entry);
                size--;
                return;
            }
        }
    }

    public boolean containsKey(K key) {
        return get(key) != null;
    }

    public int size() {
        return size;
    }

    @SuppressWarnings("unchecked")
    private void resize() {
        LinkedList<Entry<K, V>>[] oldTable = table;
        table = new LinkedList[oldTable.length * 2];
        for (int i = 0; i < table.length; i++) {
            table[i] = new LinkedList<>();
        }
        size = 0;

        for (LinkedList<Entry<K, V>> bucket : oldTable) {
            for (Entry<K, V> entry : bucket) {
                put(entry.key, entry.value); // Rehash entries into the new table
            }
        }
    }

    public static void main(String[] args) {
        MyHashMap<String, Integer> map = new MyHashMap<>();
        map.put("one", 1);
        map.put("two", 2);
        System.out.println(map.get("one")); // Should print 1
        System.out.println(map.containsKey("two")); // Should print true
        map.remove("one");
        System.out.println(map.get("one")); // Should print null
        System.out.println(map.size()); // Should print 1
    }
}