TimeConvert.java

// https://www.hackerrank.com/challenges/time-conversion

import java.util.*;

public class TimeConvert {

    public static void main(String[] args) 
    {
        Scanner sc = new Scanner(System.in);
        String[] time = sc.nextLine().split(":");
        
        String hours = time[0];
        String minutes = time[1];
        String seconds = time[2].substring(0,2);
        String dayEve = time[2].substring(2,4);
        if(dayEve.equals("AM"))
        {
        	//used Conditional Operator ( ? : )
        	//http://www.tutorialspoint.com/java/java_basic_operators.htm
            System.out.println((hours.equals("12")?"00":hours) +":"+minutes+":"+seconds);
        }
        else
        {
            System.out.println((hours.equals("12")?hours:(Integer.parseInt(hours)+12))+":"+minutes+":"+seconds);
        }
    }
}