View Compilation Error

0_0_21088854_10503.cpp: In function 'bool dfs(int, int, int, int)':
0_0_21088854_10503.cpp:33:21: error: 'dr' was not declared in this scope
         int x = r + dr[i];
                     ^
0_0_21088854_10503.cpp:34:21: error: 'dc' was not declared in this scope
         int y = c + dc[i];
                     ^