Compilare: user.cpp: In function ‘int main(int, const char**)’: user.cpp:186:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < lst.size(); i ++ ) { ^ user.cpp:189:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int j = 0; j < lst[i].size(); j ++ ) { ^ user.cpp:193:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < upd.size(); i ++ ) { ^ user.cpp:195:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int j = 0; j <= lst[i].size(); j ++ ) { ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:18:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^