P10643 [NordicOI 2022] Hipster Jazz
Background
Translated from Nordic Olympiad in Informatics 2022 [Hipster Jazz](https://noi22.kattis.com/contests/noi22/problems/hipsterjazz)。If you find that the SPJ is broken, please contact the problem porter qvq。
$\texttt{1s,1G}$。
Description
In the jazz school, a new class has been formed。There are $N$ students in this class, with $M$ pairs of friendships。Each student has to choose one main instrument: piano, or saxophone。Of course, all students want to become creative jazz musicians, so they want to ensure that at least half of their friends choose a different instrument from their own。
The students realized that choosing instruments is difficult。So they came to you, hoping that you can choose a main instrument for each student and satisfy the condition above。
The testdata guarantees that at least one solution exists。
Input Format
The first line contains two positive integers $N, M$, with meanings as described in the statement。
The next $M$ lines each contain two numbers $a, b$, meaning that $a$ and $b$ are friends。
It is guaranteed that the same pair of friends will not be listed twice。It is guaranteed that at least one solution exists。
Output Format
Output a single line containing a string of $N$ characters。The $i$-th character is `P`, meaning the $i$-th student chooses piano; the $i$-th character is `S`, meaning the $i$-th student chooses saxophone。
Explanation/Hint
#### Constraints
- $1 \le N \le 200$;
- $0 \le M \le \dfrac{N(N-1)}{2}$;
- The same pair of friends will not be listed twice;
- At least one solution exists。
#### Subtasks
| Subtask ID | Score | Constraint |
| :--: | :--: | :--: |
| $1$ | $10$ | Every pair of students are friends |
| $2$ | $15$ | $N \le 15$ |
| $3$ | $25$ | There exists a solution where every pair of friends choose different instruments |
| $4$ | $50$ | No additional constraints |
Translated by ChatGPT 5