Interview Question: find the angle between hour hand and minute hand

Recently, I gave interview on the reputed company in silicon valley, I figure out the solution to that problem with solution in android.

Question: 
How do you find the angle between hour hand and minute hand with two input field, one is an hour and next one is minute and click the button find the angle, and calculate the angle between two input in textview.
Time: 30 Minute

Solution:
They given me, Hour: 6  and Minute: 30 and output will be 15

I took the base case for hour 12:00 (h = 12, m = 0) as a reference and followed these steps.

• Calculate the angle made by hour hand with respect to 12:00 in h hours and m minutes.
• Calculate the angle made by minute hand with respect to 12:00 in h hours and m minutes.
• The difference between two angles is the angle between two hands.

And I told them if I move minute hand  360 degree in 60 minute(or 6 degree in one minute) and move hour hand  360 degree in 12 hours(or 0.5 degree in 1 minute). 

In hour hours and minute minutes, 

#  minute hand would move to the (hour*60 + minute)*6 and 

# hour hand would move to the(h*60 + m)*0.5.

if you get the confuse above equation, please put the real hour and minute value check, it would be correct.

Now, I started to coding in android

Step 1: Layout

The layout is very easy, in relative layout, you can just put textview for label and editext for input for both hour and minute and the button for click and gives output, finally, I put one textview for display out.

Here is the Layout code, if you have any confusion:

Now, I am going to write, the actual code that I have present during interview session:

Here is the Acutal output of snapshot:

I am still waiting for response!!
Happy Coding !!!

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How to use Retrofit to get data from stackoverflow API and GitHub Demo in android studio

Retrofit is a type-safe REST client for Android developed by Square. The library provides a powerful framework for authenticating and interacting with APIs and sending network requests with OkHttp. See this guide to understand how OkHttp works.

This library makes downloading JSON or XML data from a web API fairly straightforward. Once the data is downloaded then it is parsed into a Plain Old Java Object (POJO) which must be defined for each "resource" in the response.

Setup

Must be defined on internet permission on AndroidManifest.xml .

Dependencies

Add following dependencies on app/build.gradle file:

Converter:

Here is the different type of  Gson converter, we can use them:

How to create retrofit instance, 

then we have to define, the userendpoint:

Now, create model class, user variables, In MainActivity.java, we have to create instance of APIClient and call the users.

Download Full code: https://github.com/dharmakshetri/Android-API-Demos

and you can find out Awesome Retrofit Article: Retrofit Tutorial With Example In Android Studio [Step by Step]

More details:

https://square.github.io/retrofit/
https://github.com/square/retrofit
https://guides.codepath.com/android/Consuming-APIs-with-Retrofit
https://realm.io/news/droidcon-jake-wharton-simple-http-retrofit-2/
http://www.vogella.com/tutorials/Retrofit/article.html


Happy Coding !!!

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