Print n Longest Lines

Sudarshan Kasar

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Dec 28, 2020

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import java.util.*;
/**
 * Print n Longest Lines
 * Programming challenge description:
 * Write a program that finds the N longest lines from standard input.
 * Input:
 * Your program should read lines of text from standard input.
 * The first line contains the value of N, which will be a positive integer.
 * Ignore empty lines in the input. You can assume that your program will receive at least N non-empty lines.
 * Output:
 * Print to standard output the longest N lines from the input, sorted from longest line to shortest.
 * Ensure that there are no trailing spaces on each line you print nor extra empty lines between your output lines.
*/
public class PrintLongestNLines {

  public static void main(String[] args) {
    System.out.println("======= starting application===");
    List<InputLine> inputLines = new ArrayList<InputLine>();

    Scanner scanner = new Scanner(System.in);

    while (scanner.hasNext()) {
      String nextLine = scanner.next().trim();

      if(nextLine.length() > 0)
        inputLines.add(new InputLine(nextLine));

    }

    int linesToPrint = Integer.parseInt(inputLines.get(0).toString());

    scanner.close();

    Collections.sort(inputLines);

    List<InputLine> validLines = inputLines.subList(0, linesToPrint);
    for (InputLine validLine: validLines) {
      System.out.println(validLine);
    }

  }


}


class InputLine implements Comparable<InputLine> {
  private String line;

  public InputLine(String line){
    this.line = line;
  }

  @Override
  public String toString() {
    return line;
  }

  @Override
  public int compareTo(InputLine o) {
    return this.line.length() - o.line.length();
  }
}