Hey, It may seem obvious but I think contest strategy can be as important as actual problem solving skills. I have nearly zero experience on IOI style contests so this is why I open this post :D What is your strategy on this type of contests?

There is an array A of N numbers and some number K(you will be given N and K. N<1000,sqrt(N)<=K<=N). You can only query for K indices( indices are a subset of {0,1...N-1} ) and you will get them in sorted order.

What is the best strategy for sorting this array in minimum number of queries?

Problem: You are given an aray of N elements(N<1e6). You have to find maximal average of some continuous part of array. Minumum length of part=A, Maximum length =B (A,B<N).

Example: A=2,B=4,array={1,-3,6,2,5} Answer: 4.333

How to solve this problem?