Difference between two given times

Given two times in string “HH:MM” format. Here ‘H’ shows hours and ‘M’ shows minutes. You have to find the difference in same string format between these two strings. But both given strings should follow these cases.
1) Time 1 will be less than or equal to time2
2) Hours will be possible from 0 to 23.
3) Minutes will be possible from 0 to 59

Examples:

Input : s1 = "14:00";
        s2 = "16:45";
Output : result = "2:45"

Input : s1 = "1:04"
        s2 = "13:05"
Output : result = "12:01"



The idea is to first remove colon. After removing colon, hour difference can be computed using simple mathematics.

filter_none

edit
close

play_arrow

link
brightness_4
code

// C++ program to find difference between two
// given times.
#include <bits/stdc++.h>
using namespace std;
  
// remove ':' and convert it into an integer
int removeColon(string s)
{
    if (s.size() == 4) 
        s.replace(1, 1, "");
      
    if (s.size() == 5) 
        s.replace(2, 1, "");
      
    return stoi(s);
}
  
// Main function which finds difference
string diff(string s1, string s2)
{
  
    // change string (eg. 2:21 --> 221, 00:23 --> 23)
    int time1 = removeColon(s1);
    int time2 = removeColon(s2);
  
    // difference between hours
    int hourDiff = time2 / 100 - time1 / 100 - 1;
  
    // difference between minutes
    int minDiff = time2 % 100 + (60 - time1 % 100);
  
    if (minDiff >= 60) {
        hourDiff++;
        minDiff = minDiff - 60;
    }
  
    // convert answer again in string with ':'
    string res = to_string(hourDiff) + ':' + to_string(minDiff);
    return res;
}
  
// Driver program to test above functions
int main()
{
    string s1 = "14:00";
    string s2 = "16:45";
    cout << diff(s1, s2) << endl;
    return 0;
}

chevron_right


Output:

2:45

This article is contributed by Harshit Agrawal. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.



My Personal Notes arrow_drop_up


Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.