hdu 2952 Counting Sheep

题意：这道题用广搜，与hdu 1241 Oil Deposits题，是一样的。

java代码：

import java.util.ArrayList;
import java.util.Scanner;

public class Main {
	/*
	 * t表示测试事件的个数
	 * h表示行
	 * w表示列
	 * Node2952保存数据的对象数组，相当于c++的结构体。
	 * dir表示四个方向，上下左右
	 */
	static int t, h, w;
	static Node2952[][] map = new Node2952[101][101];
	static int dir[][] = { { -1, 0 }, { 1, 0 }, { 0, -1 }, { 0, 1 } };
	static MyQueue2952 mq = new MyQueue2952();

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		t = sc.nextInt();
		while (t-- > 0) {
			h = sc.nextInt();
			w = sc.nextInt();
			for (int i = 0; i < h; i++) {
				String str = sc.next();
				for (int j = 0; j < w; j++) {
					map[i][j] = new Node2952(i, j, str.charAt(j));
				}
			}
			int count = 0;
			for (int i = 0; i < h; i++) {
				for (int j = 0; j < w; j++) {
					if (map[i][j].c == '#') {
						map[i][j].c = '.';
						breadthFirstSearch(i, j);
						count++;
					}
				}
			}
			System.out.println(count);
		}
	}

	/*
	 * breadthFirstSearch广度优先搜索
	 * x,y表示搜索源的坐标。
	 */
	private static void breadthFirstSearch(int x, int y) {
		mq.add(map[x][y]);
		while (!mq.isEmpty()) {
			Node2952 no1 = mq.pop();
			for (int i = 0; i < dir.length; i++) {
				int a = no1.x + dir[i][0];
				int b = no1.y + dir[i][1];
				// 越界
				if (a < 0 || b < 0 || a >= h || b >= w) {
					continue;
				}
				// 遇到障碍物
				if (map[a][b].c == '.') {
					continue;
				}
				map[a][b].c = '.';
				mq.add(map[a][b]);
			}
		}
	}

}

/*
 * Node表示结点
 */
class Node2952 {
	int x;
	int y;
	char c;

	public Node2952(int x, int y, char c) {
		this.x = x;
		this.y = y;
		this.c = c;
	}
}

/*
 * 加泛型的队列。
 * 用来做广搜题。
 */
class MyQueue2952 {
	ArrayList al = new ArrayList();
	int index;

	public MyQueue2952() {
		index = 0;
	}

	public void add(E no) {
		al.add(no);
		index++;
	}

	public E pop() {
		if (al.isEmpty()) {
			return null;
		}
		E nod = al.remove(0);
		index--;
		return nod;
	}

	public boolean isEmpty() {
		return al.isEmpty();
	}

}

Counting Sheep

数羊

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2603    Accepted Submission(s): 1719

Problem Description

A while ago I had trouble sleeping. 

前一段时间我有睡眠问题。

I used to lie awake, staring at the ceiling, for hours and hours. 

我曾经彻夜不睡，盯着天花板,一小时又一小时。

Then one day my grandmother suggested I tried counting sheep after I'd gone to bed. 

然后有一天，我的祖母建议我数羊，然后才上床睡觉。

As always when my grandmother suggests things, I decided to try it out. 

我每天坚持数羊。

The only problem was, there were no sheep around to be counted when I went to bed.

问题只有一个，那么就是我的身边什么时候才没有羊。

Creative as I am, that wasn't going to stop me. 

大家都是聪明人，没有什么事可以阻扰我们。

I sat down and wrote a computer program that made a grid of characters, where # represents a sheep, while . is grass (or whatever you like, just not sheep). 

我坐下来，写了一个计算机程序，这个程序可以处理字符网格，'#'表示一只羊，然而'。'表示一片草地（也可以表示他不是羊）。

To make the counting a little more interesting, I also decided I wanted to count flocks of sheep instead of single sheep. 

为了使数羊活动变的更加有趣，我决定数羊群的个数，而不是单个羊。

Two sheep are in the same flock if they share a common side (up, down, right or left). 

如果两只羊所在的图中有邻边，那么就表示这两只羊是一个羊群（四种相邻方式分别为，上下左右）。

Also, if sheep A is in the same flock as sheep B, and sheep B is in the same flock as sheep C, then sheeps A and C are in the same flock.
如果A和B是一个羊群，且B和C是一个羊群，那么A和C也是一个羊群，就是说ABC三个是一个羊群的。

Now, I've got a new problem. 

现在我遇到了一个问题。

Though counting these sheep actually helps me fall asleep, I find that it is extremely boring. 

我发现这个题极其无聊，想让你帮我计算羊群的个数，来减轻我的随眠问题。

To solve this, I've decided I need another computer program that does the counting for me. 

为了解决这个问题，我决定找另外的一台计算机来帮我计算。

Then I'll be able to just start both these programs before I go to bed, and I'll sleep tight until the morning without any disturbances. 

这样就可以方便我一边睡觉（人睡觉），一边数羊（计算机数羊）。

I need you to write this program for me.

 勇士我需要你为我写一个程序。

Input

The first line of input contains a single number T, the number of test cases to follow.
输入的第一行包含一个整数T，表示测试事件的个数。
Each test case begins with a line containing two numbers, H and W, the height and width of the sheep grid. 

每一个测试事件的起始行包含两个整数H和W分表表示单词height（高），width（宽），这两个参数表示羊栏的大小。

Then follows H lines, each containing W characters (either # or .), describing that part of the grid.

 接下来有H行数据，每一行包含W的字符，每一个字符表示一个羊圈，“#”表示羊圈有羊，“。”表示没有羊。

Output

For each test case, output a line containing a single number, 

对于每一个测试事件，在单独的一行输出结果，

the amount of sheep flock son that grid according to the rules stated in the problem description.

按照问题的标准格式，输出羊群的个数。

Notes and Constraints

注意和条件
0 < T <= 100
0 < H,W <= 100

 

Sample Input

2 4 4 #.#. .#.# #.## .#.# 3 5 ###.# ..#.. #.###

 

Sample Output

6 3

 

Source

IDI Open 2009