package algs35;
import stdlib.*;
/* ***********************************************************************
 *  Compilation:  javac FrequencyTable StdIn.java
 *  Execution:    java FrequencyTable < words.txt
 *
 *  Read in a list of words from standard input and print out
 *  each word and the number of times it appears.
 *
 *  % java Frequency < mobydick.txt | sort -rn | more
 *  13967 the
 *  6415 of
 *  6247 and
 *  4583 a
 *  4508 to
 *  4037 in
 *  2911 that
 *  2481 his
 *
 *************************************************************************/

public class XFrequencyTable<K extends Comparable<? super K>> {

  private final ST<K, Integer> st = new ST<>();

  // add 1 to the number of times key appears
  public void hit(K key) {
    Integer freq = st.get(key);
    if (freq == null) st.put(key, 1);
    else              st.put(key, freq + 1);
  }

  // return the number of times the key appears
  public int count(K key) {
    Integer freq = st.get(key);
    if (freq == null) return 0;
    else              return freq;
  }

  // print all the keys to standard output
  public void show() {
    for (K key : st.keys())
      StdOut.println(st.get(key) + " " + key);
  }


  public static void main(String[] args) {
    StdIn.fromFile ("data/mobydick.txt");

    XFrequencyTable<String> f = new XFrequencyTable<>();
    while (!StdIn.isEmpty()) {
      String key = StdIn.readString();
      f.hit(key);
    }
    f.show();


  }
}