Compilare: main.cpp: In function 'void dfs(long long int)': main.cpp:35:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (long long i=0; i<L[nod].size(); i++) ~^~~~~~~~~~~~~~ main.cpp: In function 'void drum(long long int, long long int)': main.cpp:65:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (long long i=0; i<L[nod].size(); i++) ~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:88:22: warning: array subscript has type 'char' [-Wchar-subscripts] L[change(ch1)].push_back(change(ch2)); ^ main.cpp:89:25: warning: array subscript has type 'char' [-Wchar-subscripts] grad[change(ch2)]++; ^