Compilare: main.cpp: In function 'bool _is(std::__cxx11::string)': main.cpp:43:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i + word.size() - 1 >= lg) return false; ~~~~~~~~~~~~~~~~~~~~^~~~~ main.cpp:44:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<word.size();j++){ ~^~~~~~~~~~~~ main.cpp: In function 'bool solve()': main.cpp:91:31: warning: array subscript has type 'char' [-Wchar-subscripts] bool crt = val[expr[i]]; ^ main.cpp: In function 'int main()': main.cpp:110:14: warning: array subscript has type 'char' [-Wchar-subscripts] val[c] ^= 1; ^ main.cpp:102:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bool.in","r",stdin); ^ main.cpp:103:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bool.out","w",stdout); ^