Coding question from Zonal Computing Olympiad , India.

Question

How to do the first question of 2018's Zonal computing olympiad paper.
Also , any help in things i could do to reach that level of programming where i can code these things without getting stuck.
https://www.iarcs.org.in/inoi/2018/zco2018/zco2018-question-paper.pdf

Answer 1

contain time complexity algorithms
O(n) and O Log(n)

Answer 2

the code is a type of a paradigm
algorithm
when the difference between the cake eaten by the kids are equal in the test cases there is a fight