Compilare: user.cpp: In function ‘void insert_to_trie(char*, trie*)’: user.cpp:25:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(nod->son[ch]) ^ user.cpp:26:46: warning: array subscript has type ‘char’ [-Wchar-subscripts] insert_to_trie(str+1, nod->son[ch]); ^ user.cpp:28:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] nod->son[ch] = new trie; ^ user.cpp:30:46: warning: array subscript has type ‘char’ [-Wchar-subscripts] insert_to_trie(str+1, nod->son[ch]); ^ user.cpp: In function ‘bool remove_from_trie(char*, trie*)’: user.cpp:39:47: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(remove_from_trie(str+1, nod->son[ch])) { ^ user.cpp:40:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] nod->son[ch] = 0; ^ user.cpp: In function ‘trie* get(char*, trie*)’: user.cpp:55:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(nod->son[ch]) ^ user.cpp:56:42: warning: array subscript has type ‘char’ [-Wchar-subscripts] return get(str+1, nod->son[ch]); ^ user.cpp: In function ‘int prefix_len(char*, trie*)’: user.cpp:65:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(nod->son[ch]) return 1 + prefix_len(str+1, nod->son[ch]); ^ user.cpp:65:63: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(nod->son[ch]) return 1 + prefix_len(str+1, nod->son[ch]); ^