Eroare de compilare: user.cpp:4:19: error: ‘int y1’ redeclared as different kind of symbol int n,k,i,j,x1,x2,y1,y2,aux; ^ In file included from /usr/include/features.h:357:0, from /usr/include/assert.h:37, from /usr/include/c++/4.8/cassert:43, from /usr/include/i386-linux-gnu/c++/4.8/bits/stdc++.h:33, from user.cpp:1: /usr/include/i386-linux-gnu/bits/mathcalls.h:243:1: error: previous declaration of ‘double y1(double)’ __MATHCALL (y1,, (_Mdouble_)); ^ user.cpp: In function ‘int main()’: user.cpp:15:10: error: cannot bind ‘std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}’ lvalue to ‘std::basic_istream<char>&&’ f>>x1>>y1>>x2>>y2; ^ In file included from /usr/include/c++/4.8/sstream:38:0, from /usr/include/c++/4.8/complex:45, from /usr/include/c++/4.8/ccomplex:38, from /usr/include/i386-linux-gnu/c++/4.8/bits/stdc++.h:52, from user.cpp:1: /usr/include/c++/4.8/istream:872:5: error: initializing argument 1 of ‘std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&&, _Tp&) [with _CharT = char; _Traits = std::char_traits<char>; _Tp = double(double)throw ()]’ operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp& __x) ^ In file included from /usr/include/c++/4.8/bits/stl_algobase.h:66:0, from /usr/include/c++/4.8/bits/char_traits.h:39, from /usr/include/c++/4.8/ios:40, from /usr/include/c++/4.8/istream:38, from /usr/include/c++/4.8/sstream:38, from /usr/include/c++/4.8/complex:45, from /usr/include/c++/4.8/ccomplex:38, from /usr/include/i386-linux-gnu/c++/4.8/bits/stdc++.h:52, from user.cpp:1: /usr/include/c++/4.8/bits/stl_iterator_base_funcs.h: In instantiation of ‘void std::advance(_InputIterator&, _Distance) [with _InputIterator = std::_List_iterator<int>; _Distance = double (*)(double)throw ()]’: user.cpp:17:22: required from here /usr/include/c++/4.8/bits/stl_iterator_base_funcs.h:176:71: error: invalid conversion from ‘double (*)(double)throw ()’ to ‘std::__iterator_traits<std::_List_iterator<int>, true>::difference_type {aka int}’ [-fpermissive] typename iterator_traits<_InputIterator>::difference_type __d = __n; ^