P8920 "MdOI R5" Variance
Background
Subtasks 1 to 5 use the original testdata, and Subtask 6 uses hack testdata.
Description
Given two integer sequences $a, b$ of length $n$, satisfying:
- $\forall i\in [1,n), a_i \le a_{i+1}, b_i \le b_{i+1}$.
- $\forall i\in [1,n], a_i \le b_i$.
There is a real-valued sequence $c$ of length $n$ such that $c_i \in [a_i, b_i]$. Find the maximum possible variance of $c$.
You only need to output the result after multiplying the answer by $n^2$. It is easy to prove that this is an integer.
Input Format
The first line contains one integer $n$.
The second line contains $n$ integers $a_1, a_2, \dots, a_n$.
The third line contains $n$ integers $b_1, b_2, \dots, b_n$.
Output Format
One line containing one integer, which is the answer.
Explanation/Hint
The variance of a sequence $a$ of length $n$ is $\dfrac{1}{n}\sum\limits_{i=1}^n (a_i-\overline{a})^2$, where $\overline{a}=\dfrac{1}{n}\sum\limits_{i=1}^n a_i$.
During the computation for this problem, numbers exceeding the range of `long long` may appear. In that case, you may need to use `__int128`.
We provide the following code, which can be used to output a value of type `__int128`:
``` cpp
void print(__int128 x)
{
if(x