Compilare: user.cpp: In function ‘void add_word(char*)’: user.cpp:23:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(q->sons[s[i]]==0) ^ user.cpp:24:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] q->sons[s[i]]=new trie; ^ user.cpp:25:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] q=q->sons[s[i]]; ^ user.cpp: In function ‘void delete_word(char*)’: user.cpp:36:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] q=q->sons[s[i]]; ^ user.cpp: In function ‘int words(char*)’: user.cpp:46:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(q->sons[s[i]]==0)return 0; ^ user.cpp:47:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] q=q->sons[s[i]]; ^ user.cpp: In function ‘int prefix(char*)’: user.cpp:57:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(q->sons[s[i]]==0||q->sons[s[i]]->prefix==0)return i; ^ user.cpp:57:42: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(q->sons[s[i]]==0||q->sons[s[i]]->prefix==0)return i; ^ user.cpp:58:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] q=q->sons[s[i]]; ^ user.cpp: In function ‘int main()’: user.cpp:67:30: warning: format ‘%s’ expects argument of type ‘char*’, but argument 3 has type ‘char (*)[22]’ [-Wformat=] while(scanf("%d %s",&p,&s)!=EOF) ^ user.cpp:64:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trie.in","r",stdin); ^ user.cpp:65:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trie.out","w",stdout); ^