Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:31:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a[n].v.size(); i++) { ^ In file included from /usr/include/c++/4.8/algorithm:62:0, from user.cpp:4: /usr/include/c++/4.8/bits/stl_algo.h: In instantiation of ‘_RandomAccessIterator std::__unguarded_partition(_RandomAccessIterator, _RandomAccessIterator, const _Tp&) [with _RandomAccessIterator = el*; _Tp = el]’: /usr/include/c++/4.8/bits/stl_algo.h:2307:70: required from ‘_RandomAccessIterator std::__unguarded_partition_pivot(_RandomAccessIterator, _RandomAccessIterator) [with _RandomAccessIterator = el*]’ /usr/include/c++/4.8/bits/stl_algo.h:2338:54: required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size) [with _RandomAccessIterator = el*; _Size = int]’ /usr/include/c++/4.8/bits/stl_algo.h:5475:36: required from ‘void std::sort(_RAIter, _RAIter) [with _RAIter = el*]’ user.cpp:27:26: required from here /usr/include/c++/4.8/bits/stl_algo.h:2269:19: error: passing ‘const el’ as ‘this’ argument of ‘bool el::operator<(const el&)’ discards qualifiers [-fpermissive] while (__pivot < *__last) ^