Editorial for DMOPC '14 Exam Time P6 - Math Homework
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Submitting an official solution before solving the problem yourself is a bannable offence.
Submitting an official solution before solving the problem yourself is a bannable offence.
Author:
Since the source was mentioned in the footer, you can Google HDU 5155 solution
for some initial ideas. However, the given solutions are all too slow — or
. To speed it up, you can assume each row has at least one
1
( ways to do so) and either use the Inclusion-Exclusion Principle or dynamic programming with the binomial coefficient to compute the ways with
rows and
columns for
.
Time complexity: or
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