Red and Black 

 1 #include <iostream>
 2 #include <queue>
 3 using namespace std;
 4 
 5 
 6 int m, n, s1, s2;
 7 struct Node{
 8     int i;
 9     int j;
10 };
11 char map[30][30];
12 bool visited[30][30];
13 int dir[4][2] = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
14 
15 int bfs(int s1, int s2)
16 {
17     memset(visited, 0, sizeof(visited));
18     int count = 0;
19     Node a;
20     a.i = s1;
21     a.j = s2;
22     visited[a.i][a.j] = 1;
23     queue<Node> q;
24     q.push(a);
25     count++;
26     while(!q.empty())
27     {
28         a = q.front();
29         q.pop();
30         for(int i = 0; i < 4; ++i)
31         {
32             int xx = a.i + dir[i][0];
33             int yy = a.j + dir[i][1];
34             if(xx >= 0 && xx < m && yy >= 0 && yy < n)
35             {
36                 if(map[xx][yy] == '.' && visited[xx][yy] == 0)
37                 {
38                     Node b;
39                     b.i = xx;
40                     b.j = yy;
41                     q.push(b);
42                     visited[xx][yy] = 1;
43                     count++;
44                 }
45             }
46         }
47     }
48     return count;
49 }
50 int main()
51 {
52     while(scanf("%d%d", &n, &m) && (n || m))
53     {
54         getchar();
55         for(int i = 0; i < m; ++i)
56         {
57             for(int j = 0; j < n; ++j)
58             {
59                 map[i][j] = getchar();
60                 if(map[i][j] == '@')
61                 {
62                     s1 = i;
63                     s2 = j;
64                 }
65             }
66             getchar();
67         }
68         cout << bfs(s1, s2) << endl;
69     }
70     return 0;
71 }
经过BFS的一系列训练，20分钟搞定，凑活吧
posted @ 2011-07-09 22:42  georgechen_ena  阅读(65)  评论(0)    收藏  举报