Counting strings

Question

Hi, what i'm trying to do is to count how many times every possible three-word-string (in a logical order ie 1-3, 2-4, 3-5...) occurs in a file.
public class Blandning2 {
  public static void main(String[] args) throws Exception {
     String strang;
      int count = 0;
      int rakna = 0;
          Scanner sc = new Scanner(new File("test.txt"));
          Pattern p = Pattern.compile("\\b(\\w+)\\s+(?=(\\w+)\\s+(\\w+)\\b)");
              while (sc.findWithinHorizon(p, 0) != null) {
                  MatchResult m = sc.match(); 
                  count++;
               strang = m.group(1) + " " + m.group(2) + " " + m.group(3);       
               Pattern findstrang = Pattern.compile(strang);
                Scanner scc = new Scanner(new File("test.txt"));
                while (scc.findWithinHorizon(findstrang, 0) != null) {
                  MatchResult mandra = scc.match();
                  rakna++;
                   System.out.println("string number " + count + ": " + strang);
                   System.out.println("occurs: " + rakna + " times");
} the file it reads is looks like this:
Adam Bertil Cesar David
Erik Filip Gustav Helge
Ivar Johan Kalle Ludvig
Martin Niklas Olof Petter
Adam Bertil Cesar David
Erik Filip Gustav Helge
Ivar Johan Kalle Ludvig
Martin Niklas Olof
Adam Bertil Cesar David
Erik Filip Gustav Helge
Ivar Johan Kalle Ludvig
Martin Niklas
Adam Bertil Cesar David
Erik Filip Gustav Helge
Ivar Johan Kalle Ludvig
Martinmost strings should have occurrance of 4 but eg the string " Niklas Olof Petter" should only occur once. the output for the 18 first is:
idiom number 1: Adam Bertil Cesar
occurs: 4 times
idiom number 2: Bertil Cesar David
occurs: 8 times
idiom number 3: Cesar David Erik
occurs: 8 times
idiom number 4: David Erik Filip
occurs: 8 times
idiom number 5: Erik Filip Gustav
occurs: 12 times
idiom number 6: Filip Gustav Helge
occurs: 16 times
idiom number 7: Gustav Helge Ivar
occurs: 16 times
idiom number 8: Helge Ivar Johan
occurs: 16 times
idiom number 9: Ivar Johan Kalle
occurs: 20 times
idiom number 10: Johan Kalle Ludvig
occurs: 24 times
idiom number 11: Kalle Ludvig Martin
occurs: 24 times
idiom number 12: Ludvig Martin Niklas
occurs: 24 times
idiom number 13: Martin Niklas Olof
occurs: 26 times
idiom number 14: Niklas Olof Petter
occurs: 27 times
idiom number 15: Olof Petter Adam
occurs: 27 times
idiom number 16: Petter Adam Bertil
occurs: 27 times
idiom number 17: Adam Bertil Cesar
occurs: 31 times
idiom number 18: Bertil Cesar David
occurs: 35 timesthere were 56 hits which is only logical. i realize that with this method, it might print "Adam Bertil Cesar " aso several times (four in this case) but at this stage, this isn't a problem.
anyone who can see my mistake?
thank you in advance

Answer 1

I see two major problems with that code: the regex you're generating for the inner loop won't match if the whitespace within a three-name group is anything other than a single space character, and your hit-counter never gets reset. But that's a bad approach anyway. Instead of scanning the file over and over, you should scan it just once and use a Map to store the hit counts. import java.io.*;
import java.util.*;
import java.util.regex.*;
public class Test
  public static void main(String... args) throws Exception
    Scanner sc = new Scanner(new File("test.txt"));
    Pattern p = Pattern.compile("\\b(\\w+)\\s+(?=(\\w+)\\s+(\\w+)\\b)");
    Map<String, Integer> counts = new TreeMap<String, Integer>();
    String current = null;
    int maxLen = 0;
    while (sc.findWithinHorizon(p, 0) != null)
      MatchResult m = sc.match();
      current = m.group(1) + " " + m.group(2) + " " + m.group(3);
      if (counts.get(current) == null)
        counts.put(current, 1);
      else
        counts.put(current, counts.get(current) + 1);
      maxLen = current.length() > maxLen ? current.length() : maxLen;
    int totalHits = 0;
    String spec = "%-" + (maxLen) + "s%3d%n";
    for (String key : counts.keySet())
      int hits = counts.get(key);
      System.out.printf(spec, key, hits);
      totalHits += hits;
    System.out.printf(spec, "Total hits:", totalHits);
}