Language: C++

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

int main() {
  int n,k,m;
  double ans=0;
  m=0;
  cin >> n >> k;
  vector<int> a(n);
  for(int i=0;i<n;i++)
    cin >> a.at(i);
  
  for(int j=0;j<k;j++)
    m=m+1+a.at();
  
  for(int i=1;i<n-k+1;i++){
    double an=0;
    for(int j=i;j<i+k&&a.at(j-1)<a.at(j+k-1);j++)
      an =an+1+a.at(j);
    if(an>ans)
      ans=an;
  }
  cout << max(m,ans)/2 << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:14:15: error: no matching function for call to 'std::vector<int>::at()'
   14 |     m=m+1+a.at();
      |           ~~~~^~
In file included from /usr/include/c++/14/vector:66,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_vector.h:1180:7: note: candidate: 'std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::at(size_type) [with _Tp = int; _Alloc = std::allocator<int>; reference = int&; size_type = long unsigned int]'
 1180 |       at(size_type __n)
      |       ^~
/usr/include/c++/14/bits/stl_vector.h:1180:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/stl_vector.h:1199:7: note: candidate: 'std::vector<_Tp, _Alloc>::const_reference std::vector<_Tp, _Alloc>::at(size_type) const [with _Tp = int; _Alloc = std::allocator<int>; const_reference = const int&; size_type = long unsigned int]'
 1199 |       at(size_type __n) const
      |       ^~
/usr/include/c++/14/bits/stl_vector.h:1199:7: note:   candidate expects 1 argument, 0 provided
a.cc:23:14: error: no matching function for call to 'max(int&, double&)'
   23 |   cout << max(m,ans)/2 << endl;
      |           ~~~^~~~~~~
In file included 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_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:23:14: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'double')
   23 |   cout << max(m,ans)/2 << endl;
      |           ~~~^~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:23:14: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   23 |   cout << max(m,ans)/2 << endl;
      |           ~~~^~~~~~~