Compilare: user.cpp: In function ‘int main()’: user.cpp:190:58: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int k = t, o = 0; k <= l && o < qry[p].size(); k ++ ) { ^ user.cpp:207:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( ; o < qry[p].size() && qry[p][o].b == k; o ++ ) { ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:14:38: 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); ^