Question

Really struggling to work this out…

I have a text file with data like this (17000 lines of it)

45226   1
45226   1
45226   1
45226   3
45226   5
23470   1
45226   5
45226   5
29610   4
37417   2
37417   3
37948   1

What I want to do is sort the text file (using java) so all the left numbers are grouped if the right value is 1.
or the left value is group if the right is not equal to 1 (so any other number).
for example (but doesn’t have to be like this)

3 x 45226   1
4 x 45226   MIXED
1 x 23470   1
1 x 29610   MIXED
2 x 37417   MIXED
1 x 37948   1

I know I may need to use array? or some sort of sort? but I just can’t work it out :'(

Any help, code or suggestions – greatly appreciated!

Thank you!

Answer 1

My code:

public class Sort {


private static class Counter {

    private int one;
    private int mixed;

    public void incrementOne() {
        one++;
    }

    public void incrementMixed() {
        mixed++;
    }
}

public static void main(String[] args) throws IOException {
    Map<String, Counter> map = new LinkedHashMap<String, Counter>();
    String fileName = "input.txt";
    BufferedReader reader = new BufferedReader(new FileReader(fileName));

    for (String line = reader.readLine(); line != null; line = reader.readLine()) {
        StringTokenizer tokenizer = new StringTokenizer(line);
        String key = tokenizer.nextToken();
        String value = tokenizer.nextToken();
        Counter counter = map.get(key);
        if (counter == null) {
            counter = new Counter();
            map.put(key, counter);
        }
        if (value.equals("1")) {
            counter.incrementOne();
        } else {
            counter.incrementMixed();
        }
    }
    reader.close();
    BufferedWriter writer = new BufferedWriter(new FileWriter("output.txt"));
    for(Map.Entry<String, Counter>entry:map.entrySet()){
        Counter counter = entry.getValue();
        if(counter.one>0){
            writer.write(String.valueOf(counter.one));
            writer.write(" x ");
            writer.write(entry.getKey());
            writer.write("   1");
            writer.newLine();
        }
        if(counter.mixed>0){
            writer.write(String.valueOf(counter.mixed));
            writer.write(" x ");
            writer.write(entry.getKey());
            writer.write("   MIXED");
            writer.newLine();
        }
    }
    writer.close();

}

}