Compilare: main.cpp: In function 'void solve(std::__cxx11::string)': main.cpp:84:23: warning: array subscript has type 'char' [-Wchar-subscripts] avail[root->letter].push_back(root); ^ main.cpp:89:32: warning: array subscript has type 'char' [-Wchar-subscripts] next_letter[i][s[i + 1]] = i + 1; ^ main.cpp:93:40: warning: array subscript has type 'char' [-Wchar-subscripts] vector<trie*> elim = avail[s[i]]; ^ main.cpp:94:19: warning: array subscript has type 'char' [-Wchar-subscripts] avail[s[i]].clear(); ^ main.cpp:100:56: warning: array subscript has type 'char' [-Wchar-subscripts] if(next_letter[i][(next.second)->letter] != sz) ^ main.cpp:101:48: warning: array subscript has type 'char' [-Wchar-subscripts] avail[(next.second)->letter].push_back(next.second); ^