Language: C++

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
    int n, W;
    long ans = 0;
    cin >> n >> W;

    vector<bool> p(W + 1, false); // constructed weight
    vector<int> w(n + 1, 0);  // item weight
    vector<int> v(n + 1, 0);  // item value
    vector<long long> V(W + 1, 0);  // maximum value for constructed weight
    for (int i = 1; i <= n; i++) {
        cin >> w[i] >> v[i];
    }

    p[0] = true;
    for (int k = 1; k <= n; k++) {
        for (int x = W; x >= 0; x--) {
            if (p[x] == true) {
                p[x + w[k]] = true;
                V[x + w[k]] = max(V[x + w[k]], V[x] + v[k]);
                if (x + w[k] <= W) ans = max(ans, V[x + w[k]]);
            }
        }
    }
    cout << ans << endl;

    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:24:45: error: no matching function for call to 'max(long int&, __gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type&)'
   24 |                 if (x + w[k] <= W) ans = max(ans, V[x + w[k]]);
      |                                          ~~~^~~~~~~~~~~~~~~~~~
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/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 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:24:45: note:   deduced conflicting types for parameter 'const _Tp' ('long int' and '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'})
   24 |                 if (x + w[k] <= W) ans = max(ans, V[x + w[k]]);
      |                                          ~~~^~~~~~~~~~~~~~~~~~
/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:3:
/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:24:45: note:   mismatched types 'std::initializer_list<_Tp>' and 'long int'
   24 |                 if (x + w[k] <= W) ans = max(ans, V[x + w[k]]);
      |                                          ~~~^~~~~~~~~~~~~~~~~~