atcoder#NOMURA2020B. Postdocs
Postdocs
Score : points
Problem Statement
For a string consisting of the uppercase English letters P
and D
, let the doctoral and postdoctoral quotient of be the total number of occurrences of D
and PD
in as contiguous substrings. For example, if PPDDP
, it contains two occurrences of D
and one occurrence of PD
as contiguous substrings, so the doctoral and postdoctoral quotient of is .
We have a string consisting of P
, D
, and ?
.
Among the strings that can be obtained by replacing each ?
in with P
or D
, find one with the maximum possible doctoral and postdoctoral quotient.
Constraints
- consists of
P
,D
, and?
.
Input
Input is given from Standard Input in the following format:
Output
Print one string with the maximum possible doctoral and postdoctoral quotient among the strings that can be obtained by replacing each ?
in with P
or D
.
If there are multiple such strings, you may print any of them.
PD?D??P
PDPDPDP
This string contains three occurrences of D
and three occurrences of PD
as contiguous substrings, so its doctoral and postdoctoral quotient is , which is the maximum doctoral and postdoctoral quotient of a string obtained by replacing each ?
in with P
or D
.
P?P?
PDPD