Compilare: user.cpp: In function ‘std::string transformString(const string&)’: user.cpp:61:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < 2 * S.length() + 1; i++) ^ user.cpp: In function ‘std::vector<int> Manacher(const string&)’: user.cpp:69:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < S.length(); i++) { ^ user.cpp:72:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(; i - j >= 0 && i + j < S.length() && S[i - j] == S[i + j]; j++); ^ user.cpp:83:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(; i - j >= 0 && i + j < S.length() && S[i - j] == S[i + j]; j++); ^ user.cpp: In function ‘std::vector<int> getModularInverses(std::vector<int>&, int)’: user.cpp:106:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < modInverse.size(); i++) ^ user.cpp: In function ‘std::vector<int> getBaseHashes(const string&, const std::vector<int>&, int, int, int)’: user.cpp:114:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = start + step; i < S.length(); i += step) ^ user.cpp: In function ‘void getSons(const string&, StringHasher&, const std::vector<int>&)’: user.cpp:121:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < S.length(); i++) { ^