hdu 2952 Counting Sheep

题目连接

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

Counting Sheep

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

dfs求连通块个数。。

#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<vector>
#include<map>
using std::cin;
using std::cout;
using std::endl;
using std::find;
using std::sort;
using std::map;
using std::pair;
using std::vector;
using std::multimap;
#define pb(e) push_back(e)
#define sz(c) (int)(c).size()
#define mp(a, b) make_pair(a, b)
#define all(c) (c).begin(), (c).end()
#define iter(c) decltype((c).begin())
#define cls(arr,val) memset(arr,val,sizeof(arr))
#define cpresent(c, e) (find(all(c), (e)) != (c).end())
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define tr(c, i) for (iter(c) i = (c).begin(); i != (c).end(); ++i)
const int N = 110;
typedef unsigned long long ull;
char G[N][N];
bool vis[N][N];
int H, W;
const int dx[] = { 0, 0, -1, 1 }, dy[] = { -1, 1, 0, 0 };
void dfs(int x, int y) {
    vis[x][y] = true;
    rep(i, 4) {
        int nx = x + dx[i], ny = y + dy[i];
        if (nx < 0 || nx >= H || ny < 0 || ny >= W) continue;
        if (vis[nx][ny] || G[nx][ny] == '.') continue;
        dfs(nx, ny);
    }
}
int main() {
#ifdef LOCAL
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w+", stdout);
#endif
    int t, ans;
    scanf("%d", &t);
    while (t--) {
        ans = 0;
        cls(vis, false);
        scanf("%d %d", &H, &W);
        rep(i, H) scanf("%s", G[i]);
        rep(i, H) {
            rep(j, W) {
                if (!vis[i][j] && G[i][j] == '#') ans++, dfs(i, j);
            }
        }
        printf("%d
", ans);
    }
    return 0;
}