Compilare: user.cpp: In member function ‘Trie* Trie::go_to(char)’: user.cpp:31:18: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (son[c] == NULL) son[c] = new Trie(); ^ user.cpp:31:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (son[c] == NULL) son[c] = new Trie(); ^ user.cpp:32:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] return son[c]; ^ user.cpp: In function ‘int main()’: user.cpp:45:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("enigma.in","r",stdin); ^ user.cpp:46:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("enigma.out","w",stdout); ^ user.cpp:48:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n", &n, &m); ^ user.cpp:49:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", s + 1); ^ user.cpp:56:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", aux + 1); ^