Index.java


Below is the syntax highlighted version of Index.java from §4.4 Symbol Tables.


/******************************************************************************
 *  Compilation:  javac Index.java
 *  Execution:    java Index i j < input.txt
 *  Dependencies: ST.java Queue.java StdIn.java StdOut.java
 *  Data files:   http://www.cs.princeton.edu/introcs/44st/TaleOfTwoCities.java
 *
 *  Create an index of all words in the given input file such that
 *  the word has length >= i and occurs >= j times.
 *
 *  % java Index 9 30 < TaleOfTwoCities.txt 
 *  confidence: 2794 23064 25031 34249 47907 48268 48577 ... 
 *  courtyard: 11885 12062 17303 17451 32404 32522 38663 ... 
 *  evremonde: 86211 90791 90798 90802 90814 90822 90856 ... 
 *  expression: 3777 5575 6574 7116 7195 8509 8928 15015 ... 
 *  gentleman: 2521 5290 5337 5698 6235 6301 6326 6338 ... 
 *  influence: 27809 36881 43141 43150 48308 54049 54067 ... 
 *  monseigneur: 85 90 36587 36590 36611 36636 36643 ... 
 *  prisoners: 1012 20729 20770 21240 22123 22209 22590 ... 
 *  something: 3406 3765 9283 13234 13239 15245 20257 ... 
 *  sometimes: 4514 4530 4548 6082 20731 33883 34239 ... 
 *  vengeance: 56041 63943 67705 79351 79941 79945 80225 ...
 *
 ******************************************************************************/

public class Index {
    public static void main(String[] args) {
        int minLength     = Integer.parseInt(args[0]);    // min length of word
        int minOccurrence = Integer.parseInt(args[1]);    // min number of occurrences

        // read in the words from stdin
        String[] words = StdIn.readAllStrings();

        // build symbol table of words and locations
        ST<String, Queue<Integer>> st = new ST<String, Queue<Integer>>();
        for (int i = 0; i < words.length; i++) {
            String s = words[i];
            if (s.length() < minLength) continue;
            if (!st.contains(s)) {
                st.put(s, new Queue<Integer>());
            }
            Queue<Integer> q = st.get(s);
            q.enqueue(i);
        }
        for (String s : st.keys()) { 
            Queue<Integer> q = st.get(s);
            if (q.length() >= minOccurrence) {
                StdOut.println(s + ": " + q);
            }
        } 
    } 
} 


Copyright © 2000–2017, Robert Sedgewick and Kevin Wayne.
Last updated: Fri Oct 20 14:12:12 EDT 2017.