Language: C++

#include <bits/stdc++.h>
#define fin(i, n) for (int i = 0; i < n; i++)
#define fin2(i, a, b) for (int i = a; i < b; i++)
#define ll long long

using namespace std;

int main() {
	ll n, k;
	scanf("%lld%lld", &n, &k);
	vector<ll> t(n);
	fin(i, n) scanf("%lld", &t[i]);
	ll sum = 0;
	fin(i, k) sum += t[i];
	ll summ = sum;
	ll ind = 0;
	fin2(i, k, n) {
		sum += t[i] - t[i - k];
		if (sum > summ) {
			summ = sum;
			ind = i - k + 1;
		}
	}
	ll sump = sum;
	fin(i, n) if (i < ind || i >= ind + k) sump += max(0, t[i]);
	cout << max(0, sump);
}

Compiler output:
a.cc: In function 'int main()':
a.cc:25:59: error: no matching function for call to 'max(int, __gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type&)'
   25 |         fin(i, n) if (i < ind || i >= ind + k) sump += max(0, t[i]);
      |                                                        ~~~^~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/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:25:59: note:   deduced conflicting types for parameter 'const _Tp' ('int' and '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'})
   25 |         fin(i, n) if (i < ind || i >= ind + k) sump += max(0, t[i]);
      |                                                        ~~~^~~~~~~~~
/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:25:59: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   25 |         fin(i, n) if (i < ind || i >= ind + k) sump += max(0, t[i]);
      |                                                        ~~~^~~~~~~~~
a.cc:26:20: error: no matching function for call to 'max(int, long long int&)'
   26 |         cout << max(0, sump);
      |                 ~~~^~~~~~~~~
/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:26:20: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   26 |         cout << max(0, sump);
      |                 ~~~^~~~~~~~~
/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
/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:26:20: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   26 |         cout << max(0, sump);
      |                 ~~~^~~~~~~~~