TheOtherClock

import java.util.Scanner;
/**
 * Tuenti Programming Contest
 * Challenge 13: The other clock
 * @author alefhidalgo [at] gmail [dot] com
 */
public class TheOtherClock {

    public static final int SECOND_ZERO_LEDS = 36; /*Total leds ON at t=0*/
    private int[] ledDisplay;
    private int[] lastLedDisplay;
    {   /* initialization block */
        ledDisplay = new int[6];
        lastLedDisplay = new int[6];
    }

    /**
     * getLedsVariations: Get led variations between possible digits transition
     * @param lastDigit
     * @param newDigit
     * @return
     */
    private int getLedsVariations(int lastDigit, int newDigit) {
        //all possible transitions in a led display
        if(lastDigit == 0 && newDigit == 1) return 0;
        if(lastDigit == 1 && newDigit == 2) return 4;
        if(lastDigit == 2 && newDigit == 3) return 1;
        if(lastDigit == 3 && newDigit == 4) return 1;
        if(lastDigit == 4 && newDigit == 5) return 2;
        if(lastDigit == 5 && newDigit == 6) return 1;
        if(lastDigit == 6 && newDigit == 7) return 1;
        if(lastDigit == 7 && newDigit == 8) return 4;
        if(lastDigit == 8 && newDigit == 9) return 0;
        if(lastDigit == 9 && newDigit == 0) return 1;
        if(lastDigit == 5 && newDigit == 0) return 2;
        return 0; /*no variations*/
    }

    /**
     * Get Total led variations between last and new state
     * @return
     */
    private int getTotalVariations(){
        int sumVariations = 0;
        for (int i = 0; i < ledDisplay.length; i++) {
            sumVariations += getLedsVariations (lastLedDisplay[i], ledDisplay[i]);
        }
        return sumVariations;
    }

    /**
     * Set time in the led Display
     * @param h
     * @param m
     * @param s
     */
    private void setTime(int h, int m, int s) {
        String sHours = String.valueOf(h);
        String sMin = String.valueOf(m);
        String sSec = String.valueOf(s);
        if (sHours.length() > 1) {
            ledDisplay[4] = Integer.parseInt(sHours.substring(1, 2));
            ledDisplay[5] = Integer.parseInt(sHours.substring(0, 1));
        } else {
            ledDisplay[4] = Integer.parseInt(sHours.substring(0, 1));
            ledDisplay[5] = 0;
        }

        if (sMin.length() > 1) {
            ledDisplay[2] = Integer.parseInt(sMin.substring(1, 2));
            ledDisplay[3] = Integer.parseInt(sMin.substring(0, 1));
        } else {
            ledDisplay[2] = Integer.parseInt(sMin.substring(0, 1));
            ledDisplay[3] = 0;
        }

        if (sSec.length() > 1) {
            ledDisplay[0] = Integer.parseInt(sSec.substring(1, 2));
            ledDisplay[1] = Integer.parseInt(sSec.substring(0, 1));
        } else {
            ledDisplay[0] = Integer.parseInt(sSec.substring(0, 1));
            ledDisplay[1] = 0;
        }

    }

    /**
     * getTotalLedsOn
     *  Get total leds ON in a 7 display clock from t=0 to t=seconds
     * @param seconds
     * @return
     */
    public int getTotalLedsOn(int seconds) {
        int sumLedsOn = TheOtherClock.SECOND_ZERO_LEDS;
        for (int i = 0; i <= seconds; i++) {
            int seg = i % 60;
            int min = (i / 60) % 60;
            int hours = (i / 3600) % 12;
            setTime(hours, min, seg);
            if(i>0) {
                //get only variations between off/on leds
                sumLedsOn += getTotalVariations();
            }
            //save the last display state in order to detect the variations
            System.arraycopy(ledDisplay, 0, lastLedDisplay, 0, ledDisplay.length);
        }
        return sumLedsOn;
    }

    /* For Debug purpose */
//  private void printLedDisplay() {
//      System.out.println(ledDisplay[5] + "" + ledDisplay[4] + ":" + ledDisplay[3] + "" + ledDisplay[2] + ":" + ledDisplay[1] + "" + ledDisplay[0]);
//  }
//
    public static void main(String args[]) {
        TheOtherClock theClock = new TheOtherClock();
        Scanner in = new Scanner(System.in);
        while (in.hasNextInt()) {
            System.out.println(theClock.getTotalLedsOn(in.nextInt()));
        }
    }
}