Eroare de compilare: user.cpp: In function ‘void df(int)’: user.cpp:30:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[x].size(); ++i) ^ user.cpp: In function ‘void sons(int, int)’: user.cpp:41:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[curr].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&, _Compare) [with _RandomAccessIterator = int*; _Tp = int; _Compare = bool (*)(int&, int&)]’: /usr/include/c++/4.8/bits/stl_algo.h:2319:78: required from ‘_RandomAccessIterator std::__unguarded_partition_pivot(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = bool (*)(int&, int&)]’ /usr/include/c++/4.8/bits/stl_algo.h:2360:62: required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = int*; _Size = int; _Compare = bool (*)(int&, int&)]’ /usr/include/c++/4.8/bits/stl_algo.h:5513:44: required from ‘void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = int*; _Compare = bool (*)(int&, int&)]’ user.cpp:60:21: required from here /usr/include/c++/4.8/bits/stl_algo.h:2287:35: error: invalid initialization of reference of type ‘int&’ from expression of type ‘const int’ while (__comp(*__first, __pivot)) ^ /usr/include/c++/4.8/bits/stl_algo.h:2290:34: error: invalid initialization of reference of type ‘int&’ from expression of type ‘const int’ while (__comp(__pivot, *__last)) ^