Eroare de compilare: main.cpp: In function 'int main()': main.cpp:34:37: error: invalid initialization of non-const reference of type 'std::pair<int, int>&' from an rvalue of type 'std::pair<int, int>' pair<int, int> &ball = add[x]; ~~~~~^ In file included from /usr/include/c++/6/utility:70:0, from /usr/include/c++/6/algorithm:60, from main.cpp:1: /usr/include/c++/6/bits/stl_pair.h:276:19: note: after user-defined conversion: constexpr std::pair<_T1, _T2>::pair(const std::pair<_U1, _U2>&) [with _U1 = signed char; _U2 = signed char; typename std::enable_if<(std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ConstructiblePair<_U1, _U2>() && std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ImplicitlyConvertiblePair<_U1, _U2>()), bool>::type <anonymous> = 1u; _T1 = int; _T2 = int] constexpr pair(const pair<_U1, _U2>& __p) ^~~~ Non zero exit status: 1