Eroare de compilare: user.cpp: In function ‘void read()’: user.cpp:8:16: error: lvalue required as unary ‘&’ operand #define x real() ^ user.cpp:45:34: note: in expansion of macro ‘x’ scanf("%lf %lf", &v[i].a.x, &v[i].a.y); ^ user.cpp:9:16: error: lvalue required as unary ‘&’ operand #define y imag() ^ user.cpp:45:45: note: in expansion of macro ‘y’ scanf("%lf %lf", &v[i].a.x, &v[i].a.y); ^ user.cpp:8:16: error: lvalue required as unary ‘&’ operand #define x real() ^ user.cpp:52:37: note: in expansion of macro ‘x’ scanf("%lf %lf %lf %lf", &a.x, &a.y, &b.x, &b.y); ^ user.cpp:9:16: error: lvalue required as unary ‘&’ operand #define y imag() ^ user.cpp:52:43: note: in expansion of macro ‘y’ scanf("%lf %lf %lf %lf", &a.x, &a.y, &b.x, &b.y); ^ user.cpp:8:16: error: lvalue required as unary ‘&’ operand #define x real() ^ user.cpp:52:49: note: in expansion of macro ‘x’ scanf("%lf %lf %lf %lf", &a.x, &a.y, &b.x, &b.y); ^ user.cpp:9:16: error: lvalue required as unary ‘&’ operand #define y imag() ^ user.cpp:52:55: note: in expansion of macro ‘y’ scanf("%lf %lf %lf %lf", &a.x, &a.y, &b.x, &b.y); ^ In file included from /usr/include/c++/4.8/algorithm:62:0, from /usr/include/i386-linux-gnu/c++/4.8/bits/stdc++.h:64, from user.cpp:1: /usr/include/c++/4.8/bits/stl_algo.h: In instantiation of ‘_RandomAccessIterator std::__unguarded_partition(_RandomAccessIterator, _RandomAccessIterator, const _Tp&) [with _RandomAccessIterator = Point*; _Tp = Point]’: /usr/include/c++/4.8/bits/stl_algo.h:2307:70: required from ‘_RandomAccessIterator std::__unguarded_partition_pivot(_RandomAccessIterator, _RandomAccessIterator) [with _RandomAccessIterator = Point*]’ /usr/include/c++/4.8/bits/stl_algo.h:2338:54: required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size) [with _RandomAccessIterator = Point*; _Size = int]’ /usr/include/c++/4.8/bits/stl_algo.h:5475:36: required from ‘void std::sort(_RAIter, _RAIter) [with _RAIter = Point*]’ user.cpp:62:26: required from here /usr/include/c++/4.8/bits/stl_algo.h:2269:19: error: passing ‘const Point’ as ‘this’ argument of ‘bool Point::operator<(Point)’ discards qualifiers [-fpermissive] while (__pivot < *__last) ^ user.cpp:41:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m);