Eroare de compilare: In file included from /usr/include/c++/4.8/algorithm:62:0, 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 = data*; _Tp = data]’: /usr/include/c++/4.8/bits/stl_algo.h:2307:70: required from ‘_RandomAccessIterator std::__unguarded_partition_pivot(_RandomAccessIterator, _RandomAccessIterator) [with _RandomAccessIterator = data*]’ /usr/include/c++/4.8/bits/stl_algo.h:2338:54: required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size) [with _RandomAccessIterator = data*; _Size = int]’ /usr/include/c++/4.8/bits/stl_algo.h:5475:36: required from ‘void std::sort(_RAIter, _RAIter) [with _RAIter = data*]’ user.cpp:52:21: required from here /usr/include/c++/4.8/bits/stl_algo.h:2269:19: error: passing ‘const data’ as ‘this’ argument of ‘bool data::operator<(const data&)’ discards qualifiers [-fpermissive] while (__pivot < *__last) ^ user.cpp: In function ‘int main()’: user.cpp:40:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d %d",&N,&M,&D); ^ user.cpp:47:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&val); ^