Hacker Rank Que - Convert time to military (24-hour) time

Given a time in AM/PM format, convert it to military (24-hour) time.

Note: Midnight is 12:00:00AM on a 12-hour clock and 00:00:00 on a 24-hour clock. Noon is 12:00:00PM on a 12-hour clock and 12:00:00 on a 24-hour clock.

Input Format

A time in 12-hour clock format (i.e.: hh:mm:ssAM or hh:mm:ssPM), where 01≤hh≤12.

Output Format

Convert and print the given time in 24-hour format, where 00≤hh≤23.

Sample Input

07:05:45PM
Sample Output

19:05:45
Explanation

7 PM is after noon, so you need to add 12 hours to it during conversion. 12 + 7 = 19. Minutes and seconds do not change in 12-24 hour time conversions, so the answer is 19:05:45.

Solution:
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String time = in.next();
        int hour = Integer.parseInt(time.substring(0,2));
        if(time.contains("AM"))
            {
            if(hour == 12)
                {
                printMilitiaryTime(time, -12);
            }else
                {
                printMilitiaryTime(time, 0);
            }
        }else if(time.contains("PM"))
            {
            if(hour == 12)
                {
                printMilitiaryTime(time, 0);
            }else
                {
                printMilitiaryTime(time, 12);
            }
        }      
    }
   
    private static void printMilitiaryTime(String time, Integer hrsToAdd)
        {
        Integer hour = Integer.parseInt(time.substring(0,2));
        hour = hour + hrsToAdd;
        String hrStr = "";
        if(hour == 0)
            {
            hrStr = "00";
        }else if(hour < 10)
            {
            hrStr = "0" + hour;
        }else
            {
            hrStr = hour.toString();
        }
        System.out.print(hrStr + time.substring(2,time.length()-2));
    }
}

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