Compilare: user.cpp: In function ‘Trie* update(const string&)’: user.cpp:23:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(node->sons[son[word[i]]] == NULL) { ^ user.cpp:24:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] node->sons[son[word[i]]] = new Trie(); ^ user.cpp:26:38: warning: array subscript has type ‘char’ [-Wchar-subscripts] node = node->sons[son[word[i]]]; ^ user.cpp: In function ‘void increase(int)’: user.cpp:34:52: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(index < end && node->sons[son[text[index]]]) { ^ user.cpp:35:45: warning: array subscript has type ‘char’ [-Wchar-subscripts] node = node->sons[son[text[index ++]]]; ^ user.cpp: In function ‘int main()’: user.cpp:46:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] son[i] = i - 'a'; ^ user.cpp:49:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] son[i] = i - 'A' + 26; ^