import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Scanner;

/**
 * Program to print longest words found in file.
 * 
 */
public class LongestWords {
    
    /** Order by String length in ascending order. */
    public static class MinLengthComparator implements Comparator<String> {
        public int compare(String s, String t) {
            return Integer.compare(s.length(), t.length());
        }
    }
    
    public static void main(String[] args) {
        if (args.length != 2) {
            System.err.println("Usage: java LongestWords N INPUTFILE");
            System.exit(1);
        }
        
        // Process command line arguments.
        int N = Integer.parseInt(args[0]);
        String filename = args[1];

        // Open input file.
        FileReader reader = null;
        try {
            reader = new FileReader(filename);
        } catch (FileNotFoundException e) {
            System.err.println("Error: file " + filename + " not found.");
            System.exit(1);
        }

        // Create queue ordered by length (ascending), with initial capacity N.
        PriorityQueue<String> queue = 
                new PriorityQueue<String>(N, new MinLengthComparator());
        
        // Read and process all words in file.
        Scanner scanner = new Scanner(reader);
        while (scanner.hasNext()) {
            String word = scanner.next();
            // Insert word in queue if it's long enough ...
        }
        
    }
}