Editorial for DMOPC '15 Contest 4 P4 - Great Sequence

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We use prefix sum to check whether the subarray's sum is greater than $K$ ~K~. For $a$ ~a~ and $b$ ~b~, you can use a balanced binary search tree or simply binary search for their occurrences in a precomputed list.

Time Complexity: $\mathcal{O}(N+Q \log N)$ ~\mathcal{O}(N+Q \log N)~

Comments

1

kelvin01732 commented on June 8, 2022, 6:28 p.m.

What do you mean when you say a "precomputed list." Like what are you precomputing?

1

thomas_li commented on June 8, 2022, 9:28 p.m.

You can precompute a list of all the array indices that a given value occurs at.