tasks.txt

Welcome to the Back End Engineering Test - you have 3 hours to complete it. The first three tasks are mandatory, the fourth and the fifth are optional,
do them if you have enough time. Please return only the source code of the solution to me by copying it from your favourite IDE, and pasting it to the Google
Docs document I am sending you.

Tasks can be solved in any of the programming languages Java, Go, JavaScript, Python, Scala or C / C ++, without the use of a framework. Please do not use
functions or libraries that solve a given problem in one or two lines of code. Comments within the code are welcome.

We would appreciate it if you would write an explanation of your idea on how you would solve the task in English, before you start writing the actual code. 

Good luck!


1. Write a method or a function that finds an element in a linked list, that is n places away from the end of the list, ideally with just one pass through
the list.

2. Write a method or a function that merges two sorted arrays, A and B, into A. 
The array A is initialized with a sufficient number of elements so that all values ​​from A and B can be accommodated. 
Values ​​of 0 represent "empty" elements, placed at the end of the array A, that can be filled in. 
The array A should contain all the elements from A and B in sorted order. 
The sort order of the array A should not be changed.

EXAMPLE:
Input A = [-1, 15, 0, 0, 0, 0] (effectively A is [-1, 15]) 
B = [4, 3, 2, 1]
The result is A = [-1, 1, 2, 3, 4, 15]

3. Write a method or a function that finds the first character that has exactly 2 occurrences in the input string.

EXAMPLE:
ABAACCBA-> B
ABC> ''
ABBCCA-> A

4. Write a method or a function that extracts 530000 elements from the input array containing 900000 elements, which are evenly distributed in the input set.
- as an illustration, let's say that the input data set contains 9 elements (x1, x2, ..., x9).
- possible solutions would be: (x1, x3, x5, x7, x9), (x1, x3, x4, x6, x8, x9) ... where a larger number of solutions would be a set of 5 elements
(a certain number of solutions would have 6 elements).
So it is important that all the elements of the resulting set are evenly distributed in the input set and that there is an appropriate number of them.

5. Write a method or a function that returns words in reverse order for a given text. Words are considered to be groups of letters separated by a whitespace
character. The first word of a new sentence should start with a capital letter and sentences should be separated with full stop ("."). All other words except
the first word of the input sentence should retain their initial form. Please do not use built-in string helper methods, like for example split, replace or
reverse.
EXAMPLE:
Agree with you the council does. Your apprentice Skywalker will be.
Does council the you with agree. Be will Skywalker apprentice your.