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BOI 2016, day 1

Start:2016-05-12 09:00:00
End:2016-05-12 14:00:00

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CSES - BOI 2016, day 1 - SpiralCSES - Spiral


Time limit:1.50 s
Memory limit:256 MB

A grid of size $(2n+1)\times(2n+1)$ has been constructed as follows. Number $1$ has been placed in the center square, number $2$ has been placed to the right of it, and the following numbers have been placed along the spiral counterclockwise.

Your task is to calculate answers for $q$ queries where the sum of numbers in an rectangular region in the grid is requested (modulo $10^9+7$). For example, in the following grid $n=2$ and the sum of numbers in the gray region is $74$:


The first input line contains two integers $n$ and $q$: the size of the grid and the number of queries.

After this, there are $q$ lines, each containing four integers $x_1$, $y_1$, $x_2$ and $y_2$ ($-n \le x_1\le x_2 \le n$, $-n \le y_1 \le y_2 \le n$). This means that you should calculate the sum of numbers in a rectangular region with corners $(x_1, y_1)$ and $(x_2, y_2)$.


You should output the answer for each query (modulo $10^9+7$).


2 3
0 -2 1 1
-1 0 1 0
1 2 1 2



In all subtasks $1 \le q \le 100$.

Subtask 1 (12 points)
Subtask 2 (15 points)
Subtask 3 (17 points)
Subtask 4 (31 points)
Subtask 5 (25 points)