Compilare: main.cpp: In member function 'void manacher::solve()': main.cpp:43:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<s.size();i++){ ~^~~~~~~~~ main.cpp:47:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i - lg - 1 >= 0 && i + lg + 1 < s.size() && s[i - lg - 1] == s[i + lg + 1]) lg++; ~~~~~~~~~~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:79:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pscpld.in","r",stdin); ^ main.cpp:80:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pscpld.out","w",stdout); ^