LA 4324 Ugly Windows (模拟)

https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=2325

　　考细心的模拟，开始的时候，没有注意到不能有其他窗遮盖这个条件，把模拟写成了只要能看到全部窗框就算是满足要求，所以WA了一次。不过很快就找到这个bug了，AC。

　　做法其实很简单，只要沿着边框走一遍就可以了。

代码如下：

View Code

 1 #define _clr(x) memset(x, 0, sizeof(x))
 2 #define REP(i, n) for (int i = 0; i < (n); i++)
 3 #define REP_1(i, n) for (int i = 1; i <= (n); i++)
 4 
 5 const int dir[4][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1}};
 6 bool vis[N][N];
 7 char mat[N][N];
 8 
 9 bool test(int x, int y, char ch) {
10     _clr(vis);
11     int minx = inf, miny = inf, maxx = x, maxy = y;
12     int cx = x, cy = y, cnt = 0;
13     while (!vis[cx][cy]) {
14 //        cout << cx << ends << cy << ends << cnt << endl;
15         cnt++;
16         minx = min(minx, cx), miny = min(miny, cy);
17         vis[cx][cy] = true;
18         REP(i, 4) {
19             int nx = cx + dir[i][0], ny = cy + dir[i][1];
20             if (vis[nx][ny] || mat[nx][ny] != ch) continue;
21             cx = nx, cy = ny;
22             break;
23         }
24     }
25     if (cnt >= 8) {
26         REP(d, 4) {
27             if (cx + dir[d][0] == x && cy + dir[d][1] == y) {
28                 INC(i, minx + 1, maxx - 1) {
29                     INC(j, miny + 1, maxy - 1) {
30                         if (mat[i][j] != '.') return false;
31                     }
32                 }
33                 return true;
34             }
35         }
36     }
37     return false;
38 }
39 
40 int mx[30], my[30];
41 
42 int main() {
43 //    freopen("in", "r", stdin);
44     int n, m;
45     while (~scanf("%d%d", &n, &m) && (n + m)) {
46         _clr(mat);
47         _clr(mx);
48         _clr(my);
49         REP_1(i, n) {
50             scanf("%s", &mat[i][1]);
51             REP_1(j, m) {
52                 if (mat[i][j] != '.') {
53 //                    cout << i << ends << j << endl;
54                     int id = mat[i][j] - 'A';
55                     mx[id] = i, my[id] = j;
56                 }
57             }
58         }
59         REP(i, 26) {
60 //            cout << mx[i] << ends << my[i] << endl;
61             if (mx[i] || my[i]) {
62                 if (test(mx[i], my[i], i + 'A')) putchar(i + 'A');
63             }
64         }
65         puts("");
66     }
67     return 0;
68 }

——written by Lyon

posted @ 2013-03-02 02:19 LyonLys 阅读(213) 评论(0) 编辑收藏举报

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