HDU 1241 Oil Deposits
Problem Description
The GeoSurvComp geologic survey company is responsible for detecting underground oil deposits. GeoSurvComp works with one large rectangular region of land at a time, and creates a grid that divides the land into numerous square plots. It then analyzes each plot separately, using sensing equipment to determine whether or not the plot contains oil. A plot containing oil is called a pocket. If two pockets are adjacent, then they are part of the same oil deposit. Oil deposits can be quite large and may contain numerous pockets. Your job is to determine how many different oil deposits are contained in a grid.
Input
The input file contains one or more grids. Each grid begins with a line containing m and n, the number of rows and columns in the grid, separated by a single space. If it signals the end of the input; otherwise and . Following this are m lines of n characters each (not counting the end-of-line characters). Each character corresponds to one plot, and is either ’ * ’ , representing the absence of oil, or ’ @ ', representing an oil pocket.
Output
For each grid, output the number of distinct oil deposits. Two different pockets are part of the same oil deposit if they are adjacent horizontally, vertically, or diagonally. An oil deposit will not contain more than pockets.
Sample Input
1 1
*
3 5
*@*@*
**@**
*@*@*
1 8
@@****@*
5 5
****@
*@@*@
*@**@
@@@*@
@@**@
0 0
Sample Output
0
1
2
2
Translation
一张地图由’*‘和’@‘组成,每一个’@‘代表一块油田,如果两个’@'相邻,那么可以拼成一块更大的油田,问一共有多少块独立的油田。
Idea
显然是并查集的思想,遍历每一个’@‘,将相邻的’@'放入同一个集合。
注意:观察样例,相邻指上、下、左、右、左上、右上、左下、右下八个方向。
Code
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