Zoj 2412 farm irrigation (DFS connected block)

If the pipelines in the two farmland can be directly connected, they can share a water source. There are 11 types of farmland. The pipeline must be in place. A farmland matrix will ask you at least how much water is needed.

DFS connection block problem if two adjacent farmland pipelines can be directly connected, they belong to a connection block. The question is to calculate the number of connected blocks.

#include<cstdio>#include<cstring>using namespace std;const int N = 55;char mat[N][N];int type[11][4] = {   //对应11种水管类型 按顺时针方向有管道的为1否则为0    {1, 0, 0, 1}, {1, 1, 0, 0}, {0, 0, 1, 1}, {0, 1, 1, 0},    {1, 0, 1, 0}, {0, 1, 0, 1}, {1, 1, 0, 1}, {1, 0, 1, 1},    {0, 1, 1, 1}, {1, 1, 1, 0}, {1, 1, 1, 1}};int dfs(int r, int c){    int cur = mat[r][c] - 'A';    if(cur < 0 || cur > 10) return 0;    mat[r][c] = 0;           //标记已经访问 0-'A'是小于0的    int up = mat[r - 1][c] - 'A', dw = mat[r + 1][c] - 'A',        le = mat[r][c - 1] - 'A', ri = mat[r][c + 1] - 'A';  //4个相邻块的管道类型    if(up > -1 && up < 11 && type[up][2] && type[cur][0])  dfs(r - 1, c);    if(dw > -1 && dw < 11 && type[dw][0] && type[cur][2])  dfs(r + 1, c);    if(le > -1 && le < 11 && type[le][1] && type[cur][3])  dfs(r, c - 1);    if(ri > -1 && ri < 11 && type[ri][3] && type[cur][1])  dfs(r, c + 1);    return 1;     //一个连通块中只有一个返回1}int main(){    int n, m, ans;    while (scanf("%d%d", &n, &m), n >= 0)    {        ans = 0;        memset(mat, 0, sizeof(mat));        for(int i = 1; i <= n; ++i)            scanf("%s", mat[i] + 1);        for(int i = 1; i <= n; ++i)            for(int j = 1; j <= m; ++j)                ans += dfs(i, j);        printf("%d\n", ans);    }    return 0;}

Farm Irrigation Time Limit: 2 seconds memory limit: 65536 KB

Benny has a spacious farm land to irrigate. the farm land is a rectangle, and is divided into a lot of Samll squares. water pipes are placed in these squares. different square has a different type of pipe. there are 11 types of pipes, which is marked from A to K, as Figure 1 shows.

Figure 1

Benny has a map of his farm, which is an array of marks denoting the distribution of water pipes over the whole farm. For example, if he has a map

ADCFJKIHE

Then the water pipes are distributed like
Figure 2

Several wellsprings are found in the center of some squares, so water can flow along the pipes from one square to another. if water flow crosses one square, the whole farm land in this square is irrigated and will have a good harvest in autumn.

Now Benny wants to know at least how could wellsprings shocould be found to have the whole farm land irrigated. Can you help him?

Note: In the above example, at least 3 wellsprings are needed, as those red points in Figure 2 show.

Input

There are several test cases! In each test case, the first line contains 2 integers m and n, then M lines follow. in each of these lines, there are n characters, in the range of 'A' to 'k', denoting the type of water pipe over the corresponding square. A negative M or N denotes the end of input, else you can assume 1 <= m, n <= 50.

Output

For each test case, output in one line the least number of wellsprings needed.

Sample Input

2 2DKHF3 3ADCFJKIHE-1 -1

Sample output

23

Zoj 2412 farm irrigation (DFS connected block)