Time conversion Hackerrank solution in C , Cpp  , Python 3 and Java 



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

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

Example

  •     s = 12:01:00PM   

      Return '12:01:00'.
  •    s = 12:01:00AM  
        Return '00:01:00'.

Function Description

Complete the timeConversion function in the editor below. It should return a new string representing the input time in 24 hour format.

timeConversion has the following parameter(s):

  • string s: a time in  hour format

Returns

  • string: the time in  hour format

Input Format

A single string  that represents a time in -hour clock format (i.e.:  or ).

Constraints

  • All input times are valid

Sample Input 0

07:05:45PM

Sample Output 0

19:05:45
Solution :  
Code in C :
#include<stdio.h>
#include<string.h>

int main ()
{
    char t1[10];
     scanf("%s",t1);
     int hr,mn,sec;
     hr= (t1[0]-'0')*10 + (t1[1]-'0');
     mn= (t1[3]-'0')*10+(t1[4]-'0');
     sec=(t1[6]-'0')*10+(t1[7]-'0');
     if (t1[8]=='A'&& hr==12 )
     {
         hr=00;
         
     }
     else if ( t1[8]=='P')
     {
         if ( hr==12 )
         {
             hr=12;
             
         }
         else 
         {
         hr=hr+12;      
     }
}

   printf("%02d:%02d:%02d",hr,mn,sec); 
}
Code in C++:
#include<iostream>
#include<string>
#include<cstring>
using namespace std ;
int main ()
{
    string t1;
    cin>>t1;
     int hr,mn,sec;
     hr= (t1[0]-'0')*10 + (t1[1]-'0');
     mn= (t1[3]-'0')*10+(t1[4]-'0');
     sec=(t1[6]-'0')*10+(t1[7]-'0');
     if (t1[8]=='A'&& hr==12 )
     {
         hr=00;
         
     }
     else if ( t1[8]=='P')
     {
         if ( hr==12 )
         {
             hr=12;
             
         }
         else 
         {
         hr=hr+12;      
     }
}

   printf("%02d:%02d:%02d",hr,mn,sec); 
}
Code in python :
ins = input().strip()

is_pm = ins[-2:].lower() == 'pm'
time_list = list(map(int, ins[:-2].split(':')))

if is_pm and time_list[0] < 12:
    time_list[0] += 12

if not is_pm and time_list[0] == 12:
    time_list[0] = 0

print(':'.join(map(lambda x: str(x).rjust(2, '0'), time_list)))
Code in Java :
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 sc = new Scanner(System.in);
        String s = sc.nextLine(); //07:05:45PM
        DateFormat inFormat = new SimpleDateFormat( "hh:mm:ssaa");
        DateFormat outFormat = new SimpleDateFormat( "HH:mm:ss");

        Date date = null;
        try {
            date = inFormat.parse(s); 
        }catch (ParseException e ){
            e.printStackTrace();
        }
        if( date != null ){
            String myDate = outFormat.format(date);
            System.out.println(myDate);
        }
    }

}
Please comment if you have any doubt or for any other problem .
Thanks