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] = ' '; 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! "); 87 } else { 88 bfs(); 89 for (i=0; i<n; ++i) 90 printf("%s ", ans[i]); 91 printf(" "); 92 } 93 } 94 95 return 0; 96 }