Eroare de compilare: 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 = punct*; _Tp = punct]’: /usr/include/c++/4.8/bits/stl_algo.h:2307:70: required from ‘_RandomAccessIterator std::__unguarded_partition_pivot(_RandomAccessIterator, _RandomAccessIterator) [with _RandomAccessIterator = punct*]’ /usr/include/c++/4.8/bits/stl_algo.h:2338:54: required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size) [with _RandomAccessIterator = punct*; _Size = int]’ /usr/include/c++/4.8/bits/stl_algo.h:5475:36: required from ‘void std::sort(_RAIter, _RAIter) [with _RAIter = punct*]’ user.cpp:65:29: required from here /usr/include/c++/4.8/bits/stl_algo.h:2269:19: error: passing ‘const punct’ as ‘this’ argument of ‘bool punct::operator<(const punct&)’ discards qualifiers [-fpermissive] while (__pivot < *__last) ^ user.cpp: In function ‘int main()’: user.cpp:56:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&N,&M); ^ user.cpp:58:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&V[i].x,&V[i].y); ^ user.cpp:61:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&V[i].x,&V[i].y); ^