Compilare: user.cpp: In function ‘void add_hash(int, int)’: user.cpp:71:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < Hash[x % MOD].size(); i ++ ) { ^ user.cpp: In function ‘bool cond()’: user.cpp:85:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int j = 0; j < Hash[i].size(); j ++ ) ^ user.cpp: In function ‘int main()’: user.cpp:105:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int j = 0; j < Hash[i].size(); j ++ ) { ^ user.cpp:114:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int j = 0; j < Hash[i].size(); j ++ ) { ^ user.cpp:95:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "patrate6.out", "w", stdout ); ^ user.cpp: In constructor ‘input_reader::input_reader(const char*)’: user.cpp:33:45: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread( buffer, SIZE, 1, input_file ); ^ user.cpp: In member function ‘void input_reader::advance()’: user.cpp:24:49: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread( buffer, SIZE, 1, input_file ); ^