Compilare: main.cpp: In function 'void solve(const string&)': main.cpp:31:24: warning: array subscript has type 'char' [-Wchar-subscripts] 31 | if (node->children[a[c]] == nullptr) { | ^ main.cpp:32:21: warning: array subscript has type 'char' [-Wchar-subscripts] 32 | node->children[a[c]] = new Node(); | ^ main.cpp:35:27: warning: array subscript has type 'char' [-Wchar-subscripts] 35 | node = node->children[a[c]]; | ^