Editorial for TLE '16 Contest 7 P3 - NOR
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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:
It is not necessary to use a segment tree or a sparse table to solve this problem. These approaches are overkill and run quite slowly. Binary search is also not necessary, and it increases execution time.
The first observation is that , where
can be any expression. In particular, if
, then the answer to the query
is always
.
To solve a query, it is only necessary to get the largest that satisfies both
and
. In case
are all
0
's, let . This information can be preprocessed and stored in an array in
time (linear time). Now there are
cases to consider:
: In this case, all integers are equal to
.
: In this case, only the first integer is equal to
. The rest are equal to
.
: In this case,
, because
and
.
A query can be solved in (constant time). Make sure to print the correct answer for each case.
Time Complexity:
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