Compilare: user.cpp: In member function ‘void trie::ins(char*, int)’: user.cpp:28:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(this -> v[*s] == NULL) ^ user.cpp:30:29: warning: array subscript has type ‘char’ [-Wchar-subscripts] this -> v[*s] = new trie; ^ user.cpp:34:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] this -> v[*s] -> ins(s + 1, pos); ^ user.cpp: In function ‘char* converter(int)’: user.cpp:74:11: warning: variable ‘p’ set but not used [-Wunused-but-set-variable] char* p; ^ user.cpp: In function ‘int main()’: user.cpp:88:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^ user.cpp:92:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &x[i]); ^