Can you give me an example?

Lets say a ={1.2.3.4.5}

and query: (2,3)

What should the answer be?

If I will met this problem in contest I will write in this way

Let's create some array $$$b$$$ where we save pair {$$$ a[i], i $$$} to sort them and save every position of element which largest one in array, and after that we can create simple segment sum tree, and answer for every query $$$x$$$ is position of element and $$$y$$$ is position of element + $$$y$$$ — 1

Upd2: My approach is wrong, I am solving problem for finding x th largest number and add y consecutive numbers

Upd: There is the approach https://ideone.com/7to9IH

Time complexity $$$O(n + mlog(n))$$$

If TL is high enough there is a $$$O(n \cdot m)$$$ solution. For each query just calculate the needed sums and use k-th statistics which works in $$$O(n)$$$.

Can you provide link to the problem?