Knowing the fact that 1D Fenwick Trees can be built in linear time, I am assuming that the 2D version can be built in quadratic time. I didn't manage to find anything about this. Can you help me with some links/ideas?
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Knowing the fact that 1D Fenwick Trees can be built in linear time, I am assuming that the 2D version can be built in quadratic time. I didn't manage to find anything about this. Can you help me with some links/ideas?
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For every updation in linear Fenwick tree we require O(log N ) time complexity.It takes Nlog(N) for linear or 1-D. sebi420p How can we built in just O(N) .
Actually, we can build a bit in O(n). Every index in a bit indicates the sum of the range [i — lowbit(i), i]. So, if you build a prefix sum array beforehand, you can use it to build the bit in O(n).
You can check this link
Thanks, that's a better way to build a bit.
Thank you!
Why is he downvoted, it's a good question.
I was wondering that too..
okwedook Thank you.