- Time limit: 1.00 s
- Memory limit: 512 MB
You are given an n \times n grid representing the map of a forest. Each square is either empty or contains a tree. The upper-left square has coordinates (1,1), and the lower-right square has coordinates (n,n).
Your task is to process q queries of the form: how many trees are inside a given rectangle in the forest?
The first input line has two integers n and q: the size of the forest and the number of queries.
Then, there are n lines describing the forest. Each line has n characters:
. is an empty square and
* is a tree.
Finally, there are q lines describing the queries. Each line has four integers y_1, x_1, y_2, x_2 corresponding to the corners of a rectangle.
Print the number of trees inside each rectangle.
- 1 \le n \le 1000
- 1 \le q \le 2 \cdot 10^5
- 1 \le y_1 \le y_2 \le n
- 1 \le x_1 \le x_2 \le n
4 3 .*.. *.** **.. **** 2 2 3 4 3 1 3 1 1 1 2 2
3 1 2