// Exercise 3.1.2 (Solution published at http://algs4.cs.princeton.edu/)
package algs31;
import stdlib.*;
import algs13.Queue;
/* ***********************************************************************
 *  Compilation:  javac ArrayST.java
 *  Execution:    java ArrayST < input.txt
 *  Dependencies: StdIn.java StdOut.java
 *  Data files:   http://algs4.cs.princeton.edu/31elementary/tinyST.txt
 *
 *
 *  Symbol table implementation with unordered array. Uses repeated
 *  doubling to resize the array.
 *
 *  % java ArrayST < tiny.txt
 *  S 0
 *  H 5
 *  X 7
 *  R 3
 *  C 4
 *  L 11
 *  A 8
 *  M 9
 *  P 10
 *  E 12
 *
 *************************************************************************/

public class ArrayST<K, V> {
  private static final int INIT_SIZE = 8;

  private V[] vals;   // symbol table values
  private K[] keys;   // symbol table keys
  private int N = 0;  // number of elements in symbol table

  @SuppressWarnings("unchecked")
  public ArrayST() {
    keys = (K[]) new Object[INIT_SIZE];
    vals = (V[]) new Object[INIT_SIZE];
  }

  // return the number of key-value pairs in the symbol table
  public int size() { return N; }

  // is the symbol table empty?
  public boolean isEmpty() { return size() == 0; }

  // resize the parallel arrays to the given capacity
  @SuppressWarnings("unchecked")
  private void resize(int capacity) {
    if (capacity <= N) throw new IllegalArgumentException ();
    K[] tempk = (K[]) new Object[capacity];
    V[] tempv = (V[]) new Object[capacity];
    for (int i = 0; i < N; i++) tempk[i] = keys[i];
    for (int i = 0; i < N; i++) tempv[i] = vals[i];
    keys = tempk;
    vals = tempv;
  }

  // insert the key-value pair into the symbol table
  public void put(K key, V val) {

    // to deal with duplicates
    delete(key);

    // double size of arrays if necessary
    if (N >= vals.length) resize(2*N);

    // add new key and value at the end of array
    vals[N] = val;
    keys[N] = key;
    N++;
  }

  public boolean contains(K key) { return get(key) != null; }
  public V get(K key) {
    for (int i = 0; i < N; i++)
      if (keys[i].equals(key)) return vals[i];
    return null;
  }

  public Iterable<K> keys() {
    Queue<K> queue = new Queue<>();
    for (int i = 0; i < N; i++)
      queue.enqueue(keys[i]);
    return queue;
  }

  // remove given key (and associated value)
  public void delete(K key) {
    for (int i = 0; i < N; i++) {
      if (key.equals(keys[i])) {
        keys[i] = keys[N-1];
        vals[i] = vals[N-1];
        keys[N-1] = null;
        vals[N-1] = null;
        N--;
        return;
      }
    }
  }




  /* *********************************************************************
   * Test routine.
   **********************************************************************/
  public static void main(String[] args) {
    StdIn.fromFile("data/tiny.txt");

    String[] a = StdIn.readAll().split("\\s+");
    int N = a.length;
    ArrayST<String, Integer> st = new ArrayST<>();
    for (int i = 0; i < N; i++)
      st.put(a[i], i);
    for (String s : st.keys())
      StdOut.println(s + " " + st.get(s));
  }
}