View Compilation Error

0_0_15732805_31267.cpp: In function 'int dfs(int, int)':
0_0_15732805_31267.cpp:30:13: error: 'tvis' was not declared in this scope
         if (tvis[x][y]) return 1;
             ^
0_0_15732805_31267.cpp:31:9: error: 'tvis' was not declared in this scope
         tvis[x][y] = 1;
         ^