Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  int n, i;
  cin >> n;
  
  vector<int> h(n);
  for(i = 0; i < n; i++) cin > h.at(i);
  
  int a[n];
  
  a[0] = 0;
  a[1] = abs(h.at(0) - h.at(1));
  
  for(i = 2; i < n; i++){
    a[i] = min(a[i - 2] + abs(h.at(i) - h.at(i - 2)), a[i - 1] + abs(h.at(i) - h.at(i - 1)));
  }
  
  cout << a[n - 1] << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:30: error: no match for 'operator>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'})
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                          ~~~ ^ ~~~~~~~
      |                          |         |
      |                          |         __gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type {aka int}
      |                          std::istream {aka std::basic_istream<char>}
a.cc:9:30: note: candidate: 'operator>(int, __gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type {aka int})' (built-in)
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                          ~~~~^~~~~~~~~
a.cc:9:30: note:   no known conversion for argument 1 from 'std::istream' {aka 'std::basic_istream<char>'} to 'int'
In file included from /usr/include/c++/14/regex:68,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:181,
                 from a.cc:1:
/usr/include/c++/14/bits/regex.h:1176:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator>(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1176 |     operator>(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1176:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/regex.h:1236:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator>(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)'
 1236 |     operator>(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1236:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/regex.h:1329:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator>(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1329 |     operator>(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1329:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/regex.h:1403:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator>(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1403 |     operator>(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1403:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'}
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/regex.h:1497:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator>(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1497 |     operator>(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1497:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/regex.h:1573:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator>(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1573 |     operator>(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1573:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'}
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/regex.h:1673:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator>(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1673 |     operator>(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1673:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/stl_pair.h:1058:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator>(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1058 |     operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1058:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::pair<_T1, _T2>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/usr/include/c++/14/bits/stl_iterator.h:462:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator>(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  462 |     operator>(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:462:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/stl_iterator.h:507:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator>(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  507 |     operator>(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:507:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/stl_iterator.h:1714:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator>(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1714 |     operator>(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1714:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/bits/stl_iterator.h:1774:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator>(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1774 |     operator>(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1774:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/string_view:695:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  695 |     operator> (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:695:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::basic_istream<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/string_view:702:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  702 |     operator> (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:702:5: note:   template argument deduction/substitution failed:
a.cc:9:38: note:   'std::basic_istream<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
    9 |   for(i = 0; i < n; i++) cin > h.at(i);
      |                                      ^
/usr/include/c++/14/string_view:710:5: note: candid