T500971 「FSLOI Round I」Stone
题目背景
**[Chinese statement.](https://www.luogu.com.cn/problem/T460363?contestId=163361) You must submit your code at the Chinese version of the statement.**
Frank and Louis are playing a modified version of an ancient game.
题目描述
Frank and Louis are playing a game with $n$ piles of stones, where the $i$-th pile has $a_i$ stones. Denote the average of sequence $a_1,a_2,\dots,a_n$ as $x$.
Before the game starts, a positive integer not greater than $x$ is given. Frank and Louis take turns making the following moves with Frank going first:
- Choose the $i$-th and the $j$-th piles of stones $(i \neq j)$ satisfying $a_i
输入格式
无
输出格式
无
说明/提示
**Example Explanation**
In the first example, $a$ is initially $\{1,5,7,9,13\}$, and the average value $x$ of the sequence $a$ is $7$.
One possible game process follows:
1. Frank chooses $i=1,j=5$, and $a$ becomes $\{3,5,7,9,11\}$.
2. Louis chooses $i=1,j=4$, and $a$ becomes $\{5,5,7,7,11\}$.
3. Frank chooses $i=2,j=5$, and $a$ becomes $\{5,7,7,7,9\}$.
4. Louis chooses $i=1,j=5$, and $a$ becomes $\{7,7,7,7,7\}$.
5. Frank is unable to make a move, so Louis wins.
**Constraints**
**Subtasks are used in this problem.**
For all tests, it is guaranteed that:
- $1 \le T \le 10$
- $1 \le n \le 2 \times 10^5$
- $0 \le a_i \le 10^9$
- $1 \le k \le x$
- $x$ is an integer.
| Subtask Id | Score | Special Property |
| :----: | :--: | :---------: |
| $1$ | $5$ |$A$|
| $2$ | $10$ | $k=1$ |
| $3$ | $15$ | $n \le 5, T=1$|
| $4$ | $25$ | $n \le 1000$ |
| $5$ | $45$ | - |
Special Property A: $a_1=a_2=\dots=a_n$.