Written

1. Create your own linked list and write a function to find the middle element of the list.
2. Consider an array which contains alphabets from 'a' to 'z'. Write a program that uses two threads to print this array.
3. Consider an array of integers. Write a program that shifts all the zeros (0) in this array to the right. Please note that you should not use any extra array or collections.

Then I was selected and attended the second round.

I was asked how to implement the "People You May Know" concept of Facebook. Write a Java program for it. I explained the algorithm and dynamics behind it, but they told me to write the code, which was rubbish.

Second question was on patterns (.) and (*). Suppose you have a complex pattern like a.b.*cdd*e.ff*. Given a string, you need to return true or false if it matches.

(.) means any character. a.b means 'a' followed by any value, then 'b', for example, a5b.

(*) means repeated. a*b means 'a' followed by zero or more 'a's, then 'b'. For example, aaab will be true, but ab will be false.

Write code for the same which takes two inputs: one regex pattern and one sample string, and returns a boolean value whether it adheres to the regex or not.

Written:

1. Create your own linked list and write a function to find the middle element of the list.
2. Consider an array which contains alphabets from 'a' to 'z'. Write a program that uses two threads to print this using both.
3. Consider an array of integers. Write a program that shifts all the zeros (0) in this array to the right. Please note you should not use any extra array or collections.

Then I was selected and attended the second round.

I was asked how to implement the "People You May Know" concept of Facebook. Write a Java program for it. I explained the algorithm and dynamics behind it, but they asked me to write the code, which was rubbish.

Second question was on patterns ('.') and ('*'). Suppose you have a complex pattern like a.b.*cdd*e.ff*. If I give you a string, you need to return true or false if it matches.

(.) means any. For example, a.b means a (any value) b, such as a5b.

(*) means repeated. For example, a*b means a (then n number of a's) then b. For example, aaab will be true, but ab will be false.

Write code for the same which takes two inputs: one regex pattern and one sample string, and returns a boolean value whether it adheres to the regex or not.