題目連結

題解：每個點（為被修改，是#）進行一次dfs，每次dfs到的點，也就是八個方向都將  '#'  修改成  '*'，下次dfs就不用再搜尋這一點了，因為已經確定這個點和前面的點是一個部分，這樣遍歷一遍圖，如果可以dfs（i，j），ans++，最後ans就是答案了。當然也可以用bfs思路來想（點一下我QWQ）。

#include <bits/stdc++.h>

using namespace std;

const int maxn = 1e3;
int n,m;
char gra[maxn][maxn];
int dx[] = {1,1,1,-1,-1,-1,0,0};
int dy[] = {0,1,-1,1,0,-1,1,-1};
void dfs(int i, int j)
{
    gra[i][j] = '*';
    for(int k = 0; k < 8; k ++)
    {
        int tx = dx[k] + i;
        int ty = dy[k] + j;
        if(tx >= 0 && tx < n && ty >= 0 && ty < m && gra[tx][ty] == '@')
        {
            dfs(tx,ty);
        }
    }
}
int main()
{
    int ans = 0;
    while(~scanf("%d %d",&n,&m)&&n&&m)
    {
        ans = 0;
        for(int i = 0; i < n; i ++)
        {
            getchar();
            scanf("%s",gra[i]);
        }
        for(int i =0; i < n; i ++)
        {
            for(int j = 0; j < m; j ++)
            {
                if(gra[i][j] == '@')
                {
                    dfs(i,j);
                    ans ++;
                }
            }
        }
        printf("%d\n",ans);
    }
    return 0;
}
 

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 m = 0 it signals the end of the input; otherwise 1 <= m <= 100 and 1 <= n <= 100. 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 100 pockets.

Sample Input

1 1
*
3 5
*@*@*
**@**
*@*@*
1 8
@@****@*
5 5 
****@
*@@*@
*@**@
@@@*@
@@**@
0 0 

Sample Output

0
1
2
2