题目描述
Problem Description
$ N $ people took a test. The score of the $ i $th person is $ S_i $.
Due to the uneven distribution of scores, we want to convert the scores so that the average is $ A $ and the difference between the maximum and minimum values is $ B $.
The conversion is done by choosing appropriate real numbers $ P $ and $ Q $. The converted score for the $ i $th person is $P \times S_i + Q$.
Determine if there are appropriate $ P $ and $ Q $, and if so, output them.
Input Format
The input is given from the standard input in the following format:
$ N $ $ A $ $ B $ $ S_1 $ $ S_2 $ : $ S_N $
- The first line contains the number of people who took the test, an integer $N\ (2 \leq N \leq 10^5)$, the desired average after conversion, an integer $A\ (1 \leq A \leq 10^9)$, and the desired difference between the maximum and minimum values after conversion, an integer $B\ (1 \leq B \leq 10^9)$, all separated by spaces.
- The next $ N $ lines contain the score of the $ i $th person, an integer $S_i\ (0 \leq S_i \leq 10^9)$.
Output Format
If no appropriate conversion exists, output $ -1 $ on a single line.
If an appropriate conversion exists, output $ P $ and $ Q $ separated by spaces on a single line. The output is accepted if the absolute or relative error is at most $ 10^{-6} $.
End the output with a newline.
Sample Input and Output
Sample Input #1
5 2 4
2
4
6
8
10
Sample Output #1
0.5 -1
Sample Input #2
13 29 31
3
1
4
1
5
9
2
6
5
3
5
8
9
Sample Output #2
3.875 10.8173076
Sample Input #3
5 1 2
34
34
34
34
34
Sample Output #3
-1
Notes/Hints
Sample Explanation 1
With $ P = 0.5 $ and $ Q = -1 $, the scores become $ 0, 1, 2, 3, 4 $ in order, resulting in an average of $ 2 $ and a difference between the maximum and minimum values of $ 4 $.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分