Compilare: user.cpp: In function ‘void add(trie*, int)’: user.cpp:31:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (p == t.size()) ^ user.cpp: In function ‘int main()’: user.cpp:97:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < s.size() ; ++i) ^ user.cpp:101:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (aux - root && !aux -> nxt[c]) ^ user.cpp:104:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (aux -> nxt[c]) aux = aux -> nxt[c]; ^ user.cpp:104:42: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (aux -> nxt[c]) aux = aux -> nxt[c]; ^ user.cpp:54:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ahocorasick.in" , "r" , stdin); ^ user.cpp:55:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ahocorasick.out" , "w" , stdout); ^