ZOJ 2412 dfs

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int dir[4][2] = {{0, 1}, {1, 0}, {0, -1}, { -1, 0}};const int wat[][4] = {0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1};const int maxn = 50 + 10;char mp[maxn][maxn];int n, m;bool vis[maxn][maxn];void dfs(int x, int y, int id){vis[x][y] = 1;for (int i = 0; i < 4; i++)if (wat[id][i]){int tx = x + dir[i][0];int ty = y + dir[i][1];int tk = mp[tx][ty] - 'A';if (tx >= 0 && tx < n && ty >= 0 && ty < m && !vis[tx][ty] && wat[tk][(i + 2) % 4])dfs(tx, ty, tk);}}int main(int argc, char const *argv[]){while (scanf("%d%d", &n, &m) == 2 && n != -1){memset(vis, 0, sizeof(vis));for (int i = 0; i < n; i++)scanf("%s", mp[i]);int cnt = 0;for (int i = 0; i < n; i++)for (int j = 0; j < m; j++)if (!vis[i][j])dfs(i, j, mp[i][j] - 'A'), cnt++;printf("%d\n", cnt);}return 0;}

简单题。