【HDOJ】3316 Mine sweeping

简单BFS。

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cstdlib>
 5 #include <queue>
 6 using namespace std;
 7
 8 #define MAXN 105
 9
10 typedef struct node_t {
11     int x, y;
12     node_t() {}
13     node_t(int xx, int yy) {
14         x = xx; y = yy;
15     }
16 } node_t;
17
18 char map[MAXN][MAXN];
19 char ans[MAXN][MAXN];
20 bool visit[MAXN][MAXN];
21 int dir[8][2] = {
22     {-1,0},{1,0},{0,1},{0,-1},
23     {1,1},{1,-1},{-1,1},{-1,-1}
24 };
25 node_t s;
26 int n;
27
28 bool check(int x, int y) {
29     return x<0 || x>=n || y<0 || y>=n;
30 }
31
32 void bfs() {
33     int i, j, k, tmp;
34     int x, y, v;
35     int xx[8], yy[8], m;
36     queue<node_t> Q;
37     node_t nd;
38
39     memset(visit, false, sizeof(visit));
40     memset(ans, ‘.‘, sizeof(ans));
41     visit[s.x][s.y] = true;
42     for (i=0; i<n; ++i)
43         ans[i][n] = ‘\0‘;
44     Q.push(s);
45
46     while (!Q.empty()) {
47         nd = Q.front();
48         Q.pop();
49         v = m = 0;
50         for (i=0; i<8; ++i) {
51             x = nd.x + dir[i][0];
52             y = nd.y + dir[i][1];
53             if (check(x, y))
54                 continue;
55             xx[m] = x;
56             yy[m] = y;
57             ++m;
58             if (map[x][y] == ‘X‘)
59                 ++v;
60         }
61         ans[nd.x][nd.y] = v+‘0‘;
62         if (v == 0) {
63             for (i=0; i<m; ++i) {
64                 if (!visit[xx[i]][yy[i]]) {
65                     visit[xx[i]][yy[i]] = true;
66                     Q.push(node_t(xx[i], yy[i]));
67                 }
68             }
69         }
70     }
71 }
72
73 int main() {
74     int i, j;
75
76 #ifndef ONLINE_JUDGE
77     freopen("data.in", "r", stdin);
78 #endif
79
80     while (scanf("%d", &n) != EOF) {
81         for (i=0; i<n; ++i)
82             scanf("%s", map[i]);
83         scanf("%d %d", &s.x, &s.y);
84
85         if (map[s.x][s.y] == ‘X‘) {
86             printf("it is a beiju!\n\n");
87         } else {
88             bfs();
89             for (i=0; i<n; ++i)
90                 printf("%s\n", ans[i]);
91             printf("\n");
92         }
93     }
94
95     return 0;
96 }