Problem of the Day
A new programming or logic puzzle every Mon-Fri

Comments:

• Opetich - 10 years, 7 months ago

  You are program? i'm no program!

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• Max Burstein - 10 years, 7 months ago

  lol whoops. I fixed it

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• Opetich - 10 years, 7 months ago

  :) Good job in getting problems everyday. even through i don't comment regulary it still is interesting thinking of them while on the bus.

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• D - 10 years, 7 months ago

  This one's in Java 7. ReminderService.java:

  import java.io.Console;
  import java.util.Calendar;
  import java.util.concurrent.Executors;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import static java.util.concurrent.TimeUnit.MILLISECONDS;
  import static java.util.concurrent.TimeUnit.MINUTES;
  
  /**
   * Scheduling service that reads reminders from the console, and writes the
   * scheduled reminders to standard output when they're due.
   */
  public class ReminderService {
  
      public static final Pattern REMINDER_PATTERN_IN = Pattern.compile("^in (\\d+) (.*)$");
      public static final Pattern REMINDER_PATTERN_AT = Pattern.compile("^at (\\d\\d\\d\\d) (.*)$");
  
      private final ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
  
      public void start() {
          Console console = System.console();
          for (String line = console.readLine(); line != null; line = console.readLine()) {
              Matcher inMatcher = REMINDER_PATTERN_IN.matcher(line);
              Matcher atMatcher = REMINDER_PATTERN_AT.matcher(line);
              if (inMatcher.matches()) {
                  long minutes = Long.valueOf(inMatcher.group(1));
                  scheduleReminder(minutes, inMatcher.group(2));
              } else if (atMatcher.matches()) {
                  long minutes = atStringAsMinutes(atMatcher.group(1));
                  scheduleReminder(minutes, atMatcher.group(2));
              } else {
                  System.out.println("Format is \"in <minutes> <text>\" " +
                                     "or \"at <HHMM> <text>\"");
              }
          }
          scheduler.shutdownNow();
      }
  
      private long atStringAsMinutes(String atString) {
          assert atString.matches("^\\d\\d\\d\\d$");
  
          Calendar now = Calendar.getInstance();
          Calendar then = Calendar.getInstance();
          then.set(Calendar.HOUR_OF_DAY, Integer.valueOf(atString.substring(0, 2)));
          then.set(Calendar.MINUTE, Integer.valueOf(atString.substring(2, 4)));
          if (now.getTimeInMillis() > then.getTimeInMillis()) {
              // atString is already in the past; schedule for tomorrow
              then.add(Calendar.DAY_OF_YEAR, 1);
          }
  
          return MILLISECONDS.toMinutes(then.getTimeInMillis()-now.getTimeInMillis());
      }
  
      private void scheduleReminder(long minutes, final String reminderText) {
          scheduler.schedule(new Runnable() {
              @Override
              public void run() {
                  // "\007" is the ASCII bell character
                  System.out.println("\007Reminder: " + reminderText);
              }
          }, minutes, MINUTES);
      }
  }
  

  And the main method in ReminderRunner.java:

  public class ReminderRunner {
  
      public static void main(String[] args) {
          new ReminderService().start();
      }
  
  }
  

  Code reviews welcome!

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• keemz - 10 years, 7 months ago

  run in command line like so: "python reminder.py at 1215" or "python reminder.py in 12"

  
  import time
  import sys
  from threading import Timer
  
  def alert():
      print "\a"
  
  def printHelp(): 
      print "please pass the mode and time arguments like so: \"in 10\" or \"at 0900\""
      exit()
  
  if len(sys.argv) is not 3:
      printHelp()
  
  mode = sys.argv[1]
  alarmTime = sys.argv[2]
  
  #process relative alarm time
  if mode == "in":
      alarmTime = int(alarmTime) * 60
      Timer(alarmTime, alert).start()
  
  #process explicit alarm times
  elif mode == "at":
  
      #time is not in the correct format
      if not len(alarmTime) == 4:
          printHelp()
  
      #get the current time and split by HH:MM:SS
      curTime = time.strftime("%H%M%S", time.localtime())
      curHour = int(curTime[0] + curTime[1])
      curMin = int(curTime[2] + curTime[3])
      curSec = int(curTime[4] + curTime[5])
  
      alHour = int(alarmTime[0] + alarmTime[1])
      alMin = int(alarmTime[2] + alarmTime[3])
  
      delay = 0
  
      #if the current time is past the alarm, schedule for next day
      if curHour > alHour or (curHour == alHour and curMin > alMin):
          delay = 24 * 60 * 60
  
      # calculate the required delay
      hrs = (alHour - curHour) * 60 * 60
      mins =(alMin - curMin) * 60
  
      delay = delay + hrs + mins - curSec
  
      Timer(delay, alert).start()
  
  else:
      printHelp()
  
  

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