View Compilation Error

0_0_14727105_28140.cpp: In function 'bool dfs(int)':
0_0_14727105_28140.cpp:34:16: error: 'linker' was not declared in this scope
             if(linker[y] == -1 || DFS(linker[y]))
                ^
0_0_14727105_28140.cpp:34:48: error: 'DFS' was not declared in this scope
             if(linker[y] == -1 || DFS(linker[y]))
                                                ^