UVa 572 油田（DFS求连通块）

https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=513

终于开始接触图了，恩，开始接触DFS了，这道题就是求连通分量，比较简单。

 #include<iostream>
 #include<cstring>
 using namespace std;

 int m, n;                                               //记录连通块的数量
 char a[][];
 int  b[][];

 void DFS(int i, int j, int count)
 {
     if (i <  || i >= m || j <  || j >= n) return;     //在递归时出界的情况
         if(b[i][j]> || a[i][j]!='@')  return;
     b[i][j] = count;
     for (int p = -; p <= ; p++)
     {
         for (int q = -; q <= ; q++)
         {
             if (p != ||q != )  DFS(i + p, j + q, count);
         }
     }
 }

 int main()
 {
     while (cin >> m >> n && m && n)
     {
         for (int i = ; i < m; i++)
             scanf("%s", &a[i]);
         int count = ;
         memset(b, , sizeof(b));
         for (int i = ; i < m; i++)
         {
             for (int j = ; j < n; j++)
             {
                 if (b[i][j] ==  && a[i][j]=='@') DFS(i, j, ++count);
             }
         }
         cout << count << endl;
     }
     return ;
 }

2016-12-03  07:49:56