public class MyHashMap {
    public static void main(String[] args) {
        MyHashMap m = new MyHashMap();

        m.put(1, 1);
        m.put(2, 2);
        m.put(13, 13);

        System.out.println(m.get(10));
    }

    private static final int MAX_SIZE = 1000000;
    int[] items;
    int size = 10;

    public MyHashMap() {
        items = new int[size];
        initArray(items);
    }

    private void initArray(int[] items) {
        for (int i = 0; i < items.length; i++) {
            items[i] = -1;
        }
    }

    public void put(int key, int value) {
        resizeIfNeeded(key);
        items[key] = value;
    }

    private void resizeIfNeeded(int key) {
        if (key > size) {
            int newSize = calculateNewSize(key);
            resize(newSize);
        }
    }

    private int calculateNewSize(int key) {
        int tmpSize = size;
        while (tmpSize < key && tmpSize < MAX_SIZE) {
            tmpSize *= 2;
            if(tmpSize > MAX_SIZE) {
                tmpSize = MAX_SIZE;
            }
        }
        return tmpSize;
    }

    private void resize(int newSize) {
        int[] newItems = new int[newSize];
        initArray(newItems);

        System.arraycopy(items, 0, newItems, 0, items.length);
        items = newItems;
        size = newSize;
    }

    /**
     * Returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key
     */
    public int get(int key) {
        resizeIfNeeded(key);
        return items[key];
    }

    /**
     * Removes the mapping of the specified value key if this map contains a mapping for the key
     */
    public void remove(int key) {
        resizeIfNeeded(key);
        items[key] = -1;
    }
}
/**
 * Your MyHashMap object will be instantiated and called as such:
 * MyHashMap obj = new MyHashMap();
 * obj.put(key,value);
 * int param_2 = obj.get(key);
 * obj.remove(key);
 */