Language: C++

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
ll solve(vector<int> vec)
{
    ll pos_sum = 0;
    int cnt = 0;
    ll positive_min = INT_MAX;
    ll negtive_max = INT_MIN;
    ll neg_sum = 0;
    for(int x:vec)
    {
        if(x<0)
            cnt++, neg_sum += x, negtive_max = max(negtive_max, x);
        else
            positive_min = min(positive_min,x), pos_sum += x;
    }
    if(cnt % 2 == 0)
    {
        return pos_sum - neg_sum;
    }
    return max(pos_sum - neg_sum - positive_min*2, pos_sum - neg_sum + negtive_max * 2);
}
int main()
{
    int n;
    cin>>n;
    vector<int> dat(n);
    for(int i=0;i<n;++i)cin>>dat[i];
    cout<<solve(dat);
}

Compiler output:
a.cc: In function 'll solve(std::vector<int>)':
a.cc:14:51: error: no matching function for call to 'max(ll&, int&)'
   14 |             cnt++, neg_sum += x, negtive_max = max(negtive_max, x);
      |                                                ~~~^~~~~~~~~~~~~~~~
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:14:51: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   14 |             cnt++, neg_sum += x, negtive_max = max(negtive_max, x);
      |                                                ~~~^~~~~~~~~~~~~~~~
/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:14:51: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   14 |             cnt++, neg_sum += x, negtive_max = max(negtive_max, x);
      |                                                ~~~^~~~~~~~~~~~~~~~
a.cc:16:31: error: no matching function for call to 'min(ll&, int&)'
   16 |             positive_min = min(positive_min,x), pos_sum += x;
      |                            ~~~^~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:233:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::min(const _Tp&, const _Tp&)'
  233 |     min(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:233:5: note:   template argument deduction/substitution failed:
a.cc:16:31: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   16 |             positive_min = min(positive_min,x), pos_sum += x;
      |                            ~~~^~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::min(const _Tp&, const _Tp&, _Compare)'
  281 |     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5686:5: note: candidate: 'template<class _Tp> constexpr _Tp std::min(initializer_list<_Tp>)'
 5686 |     min(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5686:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5696:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::min(initializer_list<_Tp>, _Compare)'
 5696 |     min(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5696:5: note:   template argument deduction/substitution failed:
a.cc:16:31: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   16 |             positive_min = min(positive_min,x), pos_sum += x;
      |                            ~~~^~~~~~~~~~~~~~~~