Language: C++

#include <fstream>
#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
using namespace std;

int main() {
  // ifstream cin("../test.txt");
  int n;
  while (true) {
    cin >> n;
    if (!n) break;
    vector<int> a(n);
    vector<int> sub_sum(n); // a[0] + ... + a[i]
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    sub_sum[0] = a[0];
    long long max_sum = -100000000000;
    for (int i = 1; i < n; i++) {
      sub_sum[i] = sub_sum[i-1] + a[i];
      max_sum = max(max_sum, sub_sum[i]);
    }
    for (int i = 1; i < n; i++) {
      for (int j = 0; j < i; j++) {
        max_sum = max(max_sum, sub_sum[i] - sub_sum[j]);
      }
    }
    cout << max_sum << endl;
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:25:20: error: no matching function for call to 'max(long long int&, __gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type&)'
   25 |       max_sum = max(max_sum, sub_sum[i]);
      |                 ~~~^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/istream:40,
                 from /usr/include/c++/14/fstream:40,
                 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:25:20: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'})
   25 |       max_sum = max(max_sum, sub_sum[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,
                 from a.cc:7:
/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:25:20: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   25 |       max_sum = max(max_sum, sub_sum[i]);
      |                 ~~~^~~~~~~~~~~~~~~~~~~~~
a.cc:29:22: error: no matching function for call to 'max(long long int&, __gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type)'
   29 |         max_sum = max(max_sum, sub_sum[i] - sub_sum[j]);
      |                   ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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:29:22: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'})
   29 |         max_sum = max(max_sum, sub_sum[i] - sub_sum[j]);
      |                   ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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:29:22: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   29 |         max_sum = max(max_sum, sub_sum[i] - sub_sum[j]);
      |                   ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~