【HDOJ】1547 Bubble Shooter

两次BFS，一次扫描关联点。一次扫描可能掉落的情况（即再次扫描所有非爆炸的联通点）。余下未被扫描的点均爆炸。

  1 #include <cstdio>
  2 #include <cstring>
  3 #include <queue>
  4 #include <cstdlib>
  5 #include <iostream>
  6 using namespace std;
  7 
  8 #define MAXN 105
  9 char map[MAXN][MAXN];
 10 bool visit[MAXN][MAXN];
 11 int h, w, x, y;
 12 int dir[8][2] = {-1,1, 1,1, -1,0, 0,1, 1,0, 0,-1, -1,-1, 1,-1};
 13 
 14 typedef struct node_t {
 15     int x, y;
 16     node_t() {}
 17     node_t(int xx, int yy) {
 18         x = xx; y = yy;
 19     }
 20 } node_t;
 21 
 22 bool check(int x, int y) {
 23     int ww = w;
 24 
 25     if ((x&1) == 0)
 26         ww = w-1;
 27     if (x<1 || x>h || y<1 || y>ww || visit[x][y])
 28         return true;
 29     return false;
 30 }
 31 
 32 void bfs_Oth(int x, int y) {
 33     int i, j, nx, ny;
 34     queue<node_t> Q;
 35 
 36     visit[x][y] = true;
 37     Q.push(node_t(x,y));
 38 
 39     while (!Q.empty()) {
 40         node_t nd = Q.front();
 41         Q.pop();
 42         j = (nd.x & 1)<<1;
 43         for (i=j; i<j+6; ++i) {
 44             nx = nd.x + dir[i][0];
 45             ny = nd.y + dir[i][1];
 46             if (check(nx, ny) || map[nx][ny]=='E')
 47                 continue;
 48             Q.push(node_t(nx, ny));
 49             visit[nx][ny] = true;
 50         }
 51     }
 52 }
 53 
 54 void bfs() {
 55     int ans = 0;
 56     int i, j, nx, ny;
 57     char c = map[x][y];
 58     queue<node_t> Q;
 59 
 60     memset(visit, false, sizeof(visit));
 61     visit[x][y] = true;
 62     Q.push(node_t(x,y));
 63 
 64     while (!Q.empty()) {
 65         node_t nd = Q.front();
 66         Q.pop();
 67         ++ans;
 68         j = (nd.x & 1)<<1;
 69         for (i=j; i<j+6; ++i) {
 70             nx = nd.x + dir[i][0];
 71             ny = nd.y + dir[i][1];
 72             if (check(nx, ny) || map[nx][ny]!=c)
 73                 continue;
 74             Q.push(node_t(nx, ny));
 75             visit[nx][ny] = true;
 76         }
 77     }
 78 
 79     if (ans < 3) {
 80         printf("0\n");
 81         return ;
 82     }
 83 
 84     // search the other bubbles
 85     for (j=1; map[1][j]; ++j) {
 86         if (!visit[1][j] && map[1][j]!='E') {
 87             bfs_Oth(1, j);
 88         }
 89     }
 90 
 91     for (i=1; i<=h; ++i) {
 92         for (j=1; map[i][j]; ++j) {
 93             if (!visit[i][j] && map[i][j]!='E')
 94                 ++ans;
 95         }
 96     }
 97     printf("%d\n", ans);
 98 }
 99 
100 
101 int main() {
102     int i, j;
103 #ifndef ONLINE_JUDGE
104     FILE *fin = freopen("data.in", "r", stdin);
105 #endif
106     while (scanf("%d%d%d%d", &h,&w,&x,&y)!=EOF) {
107         for (i=1; i<=h; ++i) {
108             scanf("%s", map[i]+1);
109         }
110         bfs();
111 #ifndef ONLINE_JUDGE
112         fflush(stdout);
113 #endif
114     }
115 
116     return 0;
117 }

 

posted on 2014-10-13 19:05  Bombe  阅读(207)  评论(0)  编辑  收藏  举报

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