Editorial for DMOPC '18 Contest 5 P2 - A Photography Problem


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Authors: AvaLovelace

Notice that the average brightness increases with an increase in C. Thus, we can binary search for the C that would make the average brightness equal to 0.48. The maximum value C can take is 480 (when all pixel brightnesses are 10^{-3}).

Time Complexity: \mathcal O\left(NM\log_2 C\right)


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