Compilare: user.cpp: In function ‘void DFS2(int, int)’: user.cpp:30:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (!C[a][S[i][j]] && S[i][j]) ^ user.cpp:30:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (!C[a][S[i][j]] && S[i][j]) ^ user.cpp:31:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] G[a].push_back(S[i][j]), G[S[i][j]].push_back(a), C[a][S[i][j]] = 1; ^ user.cpp:31:47: warning: array subscript has type ‘char’ [-Wchar-subscripts] G[a].push_back(S[i][j]), G[S[i][j]].push_back(a), C[a][S[i][j]] = 1; ^ user.cpp:31:66: warning: array subscript has type ‘char’ [-Wchar-subscripts] G[a].push_back(S[i][j]), G[S[i][j]].push_back(a), C[a][S[i][j]] = 1; ^ user.cpp:31:75: warning: array subscript has type ‘char’ [-Wchar-subscripts] G[a].push_back(S[i][j]), G[S[i][j]].push_back(a), C[a][S[i][j]] = 1; ^ user.cpp: In function ‘bool DFS3(int)’: user.cpp:48:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[nod].size (); ++i) ^