Eroare de compilare: user.cpp: In function ‘void citire()’: user.cpp:28:6: warning: unused variable ‘x’ [-Wunused-variable] int x, y; ^ user.cpp:28:9: warning: unused variable ‘y’ [-Wunused-variable] int x, y; ^ In file included from /usr/include/c++/4.8/algorithm:62:0, from user.cpp:3: /usr/include/c++/4.8/bits/stl_algo.h: In instantiation of ‘_RandomAccessIterator std::__unguarded_partition(_RandomAccessIterator, _RandomAccessIterator, const _Tp&) [with _RandomAccessIterator = fractie*; _Tp = fractie]’: /usr/include/c++/4.8/bits/stl_algo.h:2307:70: required from ‘_RandomAccessIterator std::__unguarded_partition_pivot(_RandomAccessIterator, _RandomAccessIterator) [with _RandomAccessIterator = fractie*]’ /usr/include/c++/4.8/bits/stl_algo.h:2338:54: required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size) [with _RandomAccessIterator = fractie*; _Size = int]’ /usr/include/c++/4.8/bits/stl_algo.h:5475:36: required from ‘void std::sort(_RAIter, _RAIter) [with _RAIter = fractie*]’ user.cpp:35:17: required from here /usr/include/c++/4.8/bits/stl_algo.h:2269:19: error: passing ‘const fractie’ as ‘this’ argument of ‘bool fractie::operator<(fractie)’ discards qualifiers [-fpermissive] while (__pivot < *__last) ^ user.cpp:29:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:31:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &xes[i], &yes[i]); ^ user.cpp: In function ‘int main()’: user.cpp:56:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapez.in", "r", stdin); ^ user.cpp:57:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapez.out", "w", stdout); ^