Compilare: user.cpp: In function ‘void dfs(int, int, int, int)’: user.cpp:20:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[left][c].size(); ++i) ^ user.cpp:21:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < g[right][c].size(); ++j) ^ user.cpp: In function ‘int main()’: user.cpp:43:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] g[a[i]][t[b[i]]].push_back(b[i]); ^ user.cpp:44:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] g[b[i]][t[a[i]]].push_back(a[i]); ^