HDU 2952 Counting Sheep （搜索）

链接http://acm.hdu.edu.cn/showproblem.php?pid=2952

Problem Description

A while ago I had trouble sleeping. I used to lie awake, staring at the ceiling, for hours and hours. Then one day my grandmother suggested I tried counting sheep after I'd gone to bed. As always when my grandmother suggests things, I decided to try it out. The only problem was, there were no sheep around to be counted when I went to bed.

Creative as I am, that wasn't going to stop me. 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). To make the counting a little more interesting, I also decided I wanted to count flocks of sheep instead of single sheep. Two sheep are in the same flock if they share a common side (up, down, right or left). 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.


Now, I've got a new problem. Though counting these sheep actually helps me fall asleep, I find that it is extremely boring. To solve this, I've decided I need another computer program that does the counting for me. 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. I need you to write this program for me.

Input

The first line of input contains a single number T, the number of test cases to follow.

Each test case begins with a line containing two numbers, H and W, the height and width of the sheep grid. Then follows H lines, each containing W characters (either # or .), describing that part of the grid.

Output

For each test case, output a line containing a single number, the amount of sheep flock son that grid according to the rules stated in the problem description.

Notes and Constraints
0 < T <= 100
0 < H,W <= 100

Sample Input

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

Sample Output

6
3

题意是问有几块#，BFS 联通块模板题

做法就是从#开始搜索， 能走到的点标记下 不再搜索，  搜索几次就是几块

相连的#就算是一个区域，

HDU Oil Deposits跟这题一样，只是搜索方向增加了4个

链接http://acm.hdu.edu.cn/diy/contest_showproblem.php?pid=1011&cid=34750

#include<string.h>
#include<iostream>
#include<queue>
using namespace std;
int n, m;
char map[110][110];
int vis[110][110];
int dir[4][2] = { 0, 1, 0, -1, 1, 0, -1, 0 };
struct node{
	int x, y;
};
using namespace std;
void bfs(int x, int y){
	queue<node>q;
	q.push({ x, y });
	while (!q.empty()){
		int x = q.front().x, y = q.front().y;
		q.pop();
		if (vis[x][y])
			continue;
		vis[x][y] = 1;
		for (int i = 0; i < 4; i++){
			int xx = x + dir[i][0], yy = y + dir[i][1];
			if (xx >= 0 && xx < n&&yy >= 0 && yy < m&&map[xx][yy] == '#')
			{
				q.push({ xx, yy });
			}
		}
	}
}
int main(){
	int t;
	cin >> t;
	while (t--){
		memset(vis, 0, sizeof vis);
		cin >> n >> m;
		for (int i = 0; i < n; i++)
			cin >> map[i];
		int sum = 0;
		for (int i = 0; i < n; i++)
			for (int j = 0; j < m; j++){
				if (map[i][j] == '#' && !vis[i][j]){
					sum++;
					bfs(i, j);
				}
			}
		cout << sum << endl;
	}
	return 0;
}