JavaPalindrome2.java

import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Collections;

public class JavaPalindrome2 {

  public static void main(String[] args) throws Exception {
    String line = "";
    Long ini = System.currentTimeMillis();
    BufferedReader reader = new BufferedReader(new FileReader("seed.txt"));
    int totalPalindromes = 0;
    ArrayList<Integer> rangosMinimos = new ArrayList<Integer>();
    ArrayList<Integer> rangosMaximos = new ArrayList<Integer>();
    while ((line = reader.readLine()) != null) {
      String[] rango = line.split(" ");
      rangosMinimos.add(Integer.parseInt(rango[0]));
      rangosMaximos.add(Integer.parseInt(rango[1]));
    }
    Collections.sort(rangosMinimos);
    Collections.sort(rangosMaximos);
    int maxRango = rangosMaximos.get(rangosMaximos.size() - 1);

    for (int num = rangosMinimos.get(0); num <= maxRango; num++) {
      if (isPalindrome(num)) {
        for (int i = 0; i < rangosMinimos.size(); i++) {
          int valRangoIni = rangosMinimos.get(i);
          int valRangoFinal = rangosMaximos.get(i);
          if ((num >= valRangoIni) && (num <= valRangoFinal)) {
            totalPalindromes++;
          }
        }
      }
    }
    System.out.format("Total Palindromes: %d\n ", totalPalindromes);
    System.out.format("Duracion: %f\n", (System.currentTimeMillis() - ini) / 1000.0);
  }

  private static final boolean isPalindrome(int num) {
    String sNum = Integer.toString(num);
    for (int i = 0; i < sNum.length() / 2; i++) {
      if (sNum.charAt(i) != sNum.charAt(sNum.length() - i - 1)) {
        return false;
      }
    }
    return true;
  }
}