Language: C++

#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
void max_self(ll &a,ll b){
	a=max(a,b);
}
int main(){
	ll n,Wt;
	cin>>n>>Wt;
	vector<ll>dp[Wt+1];
	for(int item=0;item<n;item++){
		int val,w;
		cin>>val>>w;
		for(int wt_already=Wt-w;wt_already>=0;wt_already--){
			max_self(dp[wt_already+w],dp[wt_already]+val);
		}
	}
	ll ans=0;
	for(int i=0;i<=Wt;i++){
		max_self(ans,dp[i]);
	}
	cout<<ans;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:65: error: no match for 'operator+' (operand types are 'std::vector<long long int>' and 'int')
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                   ~~~~~~~~~~~~~~^~~~
      |                                                                | |
      |                                                                | int
      |                                                                std::vector<long long int>
In file included from /usr/include/c++/14/bits/stl_algobase.h:67,
                 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_iterator.h:627:5: note: candidate: 'template<class _Iterator> constexpr std::reverse_iterator<_Iterator> std::operator+(typename reverse_iterator<_Iterator>::difference_type, const reverse_iterator<_Iterator>&)'
  627 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:627:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note: candidate: 'template<class _Iterator> constexpr std::move_iterator<_IteratorL> std::operator+(typename move_iterator<_IteratorL>::difference_type, const move_iterator<_IteratorL>&)'
 1798 |     operator+(typename move_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
In file included from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/bits/basic_string.h:3598:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3598 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3598:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   'std::vector<long long int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3616:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3616 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3616:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   mismatched types 'const _CharT*' and 'std::vector<long long int>'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3635:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3635 |     operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Alloc>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3635:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3652:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3652 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3652:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   'std::vector<long long int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3670:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, _CharT)'
 3670 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3670:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   'std::vector<long long int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3682:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3682 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3682:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   'std::vector<long long int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3689:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3689 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3689:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   'std::vector<long long int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3696:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3696 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3696:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   'std::vector<long long int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3719:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3719 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3719:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   mismatched types 'const _CharT*' and 'std::vector<long long int>'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3726:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3726 |     operator+(_CharT __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3726:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   15 |                         max_self(dp[wt_already+w],dp[wt_already]+val);
      |                                                                  ^~~
/usr/include/c++/14/bits/basic_string.h:3733:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const _CharT*)'
 3733 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3733:5: note:   template argument deduction/substitution failed:
a.cc:15:66: note:   'std::vector<long long int