nikkei2019_qual_C
https://gyazo.com/4ed59c16891725e4088f629ba8803ad0
Thoughts.
Think only about the difference D=A-B since all you care about is the final score difference
If the back hand does not interfere, the first player wants to take ceil(N/2) pieces from the larger side of D.
The back hand naturally gets in the way. The biggest hindrance to the first hand is the biggest D
Therefore, the correct answer is the one taken alternately from the one with the largest D.
Official Explanation
careless mistake
D=A-B
The difference between those scores would be A+B.
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