Educational Codeforces Round 1D DFS求联通块

Posted Roni

tags:

篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了Educational Codeforces Round 1D DFS求联通块相关的知识,希望对你有一定的参考价值。

http://blog.csdn.net/snowy_smile/article/details/49924965
D. Igor In the Museum
time limit per test
 1 second
memory limit per test
 256 megabytes
input
 standard input
output
 standard output

Igor is in the museum and he wants to see as many pictures as possible.

Museum can be represented as a rectangular field of n × m cells. Each cell is either empty or impassable. Empty cells are marked with ‘.‘, impassable cells are marked with ‘*‘. Every two adjacent cells of different types (one empty and one impassable) are divided by a wall containing one picture.

At the beginning Igor is in some empty cell. At every moment he can move to any empty cell that share a side with the current one.

For several starting positions you should calculate the maximum number of pictures that Igor can see. Igor is able to see the picture only if he is in the cell adjacent to the wall with this picture. Igor have a lot of time, so he will examine every picture he can see.

Input

First line of the input contains three integers nm and k (3 ≤ n, m ≤ 1000, 1 ≤ k ≤ min(n·m, 100 000)) — the museum dimensions and the number of starting positions to process.

Each of the next n lines contains m symbols ‘.‘, ‘*‘ — the description of the museum. It is guaranteed that all border cells are impassable, so Igor can‘t go out from the museum.

Each of the last k lines contains two integers x and y (1 ≤ x ≤ n, 1 ≤ y ≤ m) — the row and the column of one of Igor‘s starting positions respectively. Rows are numbered from top to bottom, columns — from left to right. It is guaranteed that all starting positions are empty cells.

Output

Print k integers — the maximum number of pictures, that Igor can see if he starts in corresponding position.

Sample test(s)
input
5 6 3
******
*..*.*
******
*....*
******
2 2
2 5
4 3
output
6
4
10
input
4 4 1
****
*..*
*.**
****
3 2
output
8

 

以上是关于Educational Codeforces Round 1D DFS求联通块的主要内容,如果未能解决你的问题,请参考以下文章

Educational Codeforces Round 7 A

Educational Codeforces Round 7

Educational Codeforces Round 90

Educational Codeforces Round 33

Codeforces Educational Codeforces Round 54 题解

Educational Codeforces Round 27