[Solved] Competitive programming: “Time exceeded error”

Question

Calculate the cumulative sum of the array and store it in another one, that is to say,
accumulated[i] = sum of numbers of the array up to ith index. This can be computed in O(n).

Then for a query, the answer will be accumulated[r] - accumulated[l]. This is O(1)

Accepted Answer

Calculate the cumulative sum of the array and store it in another one, that is to say,
accumulated[i] = sum of numbers of the array up to ith index. This can be computed in O(n).

Then for a query, the answer will be accumulated[r] - accumulated[l]. This is O(1)