Borderou de evaluare (job #550417)

Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:50:78: error: ‘std::string’ has no member named ‘pop_back’ In file included from /usr/include/c++/4.6/algorithm:63:0, from user.cpp:4: /usr/include/c++/4.6/bits/stl_algo.h: In function ‘_RandomAccessIterator std::__unguarded_partition(_RandomAccessIterator, _RandomAccessIterator, const _Tp&, _Compare) [with _RandomAccessIterator = X*, _Tp = X, _Compare = bool (*)(X&, X&)]’: /usr/include/c++/4.6/bits/stl_algo.h:2265:78: instantiated from ‘_RandomAccessIterator std::__unguarded_partition_pivot(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = X*, _Compare = bool (*)(X&, X&)]’ /usr/include/c++/4.6/bits/stl_algo.h:2306:62: instantiated from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = X*, _Size = int, _Compare = bool (*)(X&, X&)]’ /usr/include/c++/4.6/bits/stl_algo.h:5445:4: instantiated from ‘void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = X*, _Compare = bool (*)(X&, X&)]’ user.cpp:57:20: instantiated from here /usr/include/c++/4.6/bits/stl_algo.h:2233:4: error: invalid initialization of reference of type ‘X&’ from expression of type ‘const X’ /usr/include/c++/4.6/bits/stl_algo.h:2236:4: error: invalid initialization of reference of type ‘X&’ from expression of type ‘const X’