Language: C++

#include <iostream>
#include <vector>

using namespace std;

long long helper(vector<int>& v, vector<int>& w, int W, vector<vector<long long>>& memo, int index){
	
  if(index == v.size() or W <= 0)return 0;
  
  if(memo[index][W] != 0)return memo[index][W];
  
  if(w[index] <= W){
  	memo[index][W] = max(v[index] + helper(v, w, W - w[index], memo, index + 1),
                         helper(v, w, W, memo, index + 1));
  }
  return memo[index][W];
}

int main(){
	
  int N, W;
  cin >> N >> W;
  
  vector<int> v(N);
  vector<int> w(N);
  
  for(int i = 0; i < N; i++) cin >> w[i] >> v[i];
  
  vector<vector<int>> memo(N, vector<long long>(W+1, 0));
  int res = helper(v, w, W, memo, 0);
  cout << res << endl; 
  
}
  


Compiler output:
a.cc: In function 'int main()':
a.cc:29:56: error: no matching function for call to 'std::vector<std::vector<int> >::vector(int&, std::vector<long long int>)'
   29 |   vector<vector<int>> memo(N, vector<long long>(W+1, 0));
      |                                                        ^
In file included from /usr/include/c++/14/vector:66,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_vector.h:707:9: note: candidate: 'template<class _InputIterator, class> std::vector<_Tp, _Alloc>::vector(_InputIterator, _InputIterator, const allocator_type&) [with <template-parameter-2-2> = _InputIterator; _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >]'
  707 |         vector(_InputIterator __first, _InputIterator __last,
      |         ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:707:9: note:   template argument deduction/substitution failed:
a.cc:29:56: note:   deduced conflicting types for parameter '_InputIterator' ('int' and 'std::vector<long long int>')
   29 |   vector<vector<int>> memo(N, vector<long long>(W+1, 0));
      |                                                        ^
/usr/include/c++/14/bits/stl_vector.h:678:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::initializer_list<_Tp>, const allocator_type&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; allocator_type = std::allocator<std::vector<int> >]'
  678 |       vector(initializer_list<value_type> __l,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:678:43: note:   no known conversion for argument 1 from 'int' to 'std::initializer_list<std::vector<int> >'
  678 |       vector(initializer_list<value_type> __l,
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:659:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, std::__type_identity_t<_Alloc>&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; std::__type_identity_t<_Alloc> = std::allocator<std::vector<int> >]'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:659:23: note:   no known conversion for argument 1 from 'int' to 'std::vector<std::vector<int> >&&'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |              ~~~~~~~~~^~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::false_type) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; allocator_type = std::allocator<std::vector<int> >; std::false_type = std::false_type]'
  640 |       vector(vector&& __rv, const allocator_type& __m, false_type)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:635:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::true_type) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; allocator_type = std::allocator<std::vector<int> >; std::true_type = std::true_type]'
  635 |       vector(vector&& __rv, const allocator_type& __m, true_type) noexcept
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:635:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:624:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&, std::__type_identity_t<_Alloc>&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; std::__type_identity_t<_Alloc> = std::allocator<std::vector<int> >]'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:624:28: note:   no known conversion for argument 1 from 'int' to 'const std::vector<std::vector<int> >&'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |              ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >]'
  620 |       vector(vector&&) noexcept = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:601:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >]'
  601 |       vector(const vector& __x)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:601:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:569:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const value_type&, const allocator_type&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; size_type = long unsigned int; value_type = std::vector<int>; allocator_type = std::allocator<std::vector<int> >]'
  569 |       vector(size_type __n, const value_type& __value,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:569:47: note:   no known conversion for argument 2 from 'std::vector<long long int>' to 'const std::vector<std::vector<int> >::value_type&' {aka 'const std::vector<int>&'}
  569 |       vector(size_type __n, const value_type& __value,
      |                             ~~~~~~~~~~~~~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const allocator_type&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; size_type = long unsigned int; allocator_type = std::allocator<std::vector<int> >]'
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:51: note:   no known conversion for argument 2 from 'std::vector<long long int>' to 'const std::vector<std::vector<int> >::allocator_type&' {aka 'const std::allocator<std::vector<int> >&'}
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |                             ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const allocator_type&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; allocator_type = std::allocator<std::vector<int> >]'
  542 |       vector(const allocator_type& __a) _GLIBCXX_NOEXCEPT
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:531:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector() [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >]'
  531 |       vector() = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:531:7: note:   candidate expects 0 arguments, 2 provided
a.cc:30:29: error: invalid initialization of reference of type 'std::vector<std::vector<long long int> >&' from expression of type 'std::vector<std::vector<int> >'
   30 |   int res = helper(v, w, W, memo, 0);
      |                             ^~~~
a.cc:6:84: note: in passing argument 4 of 'long long int helper(std::vector<int>&, std::vector<int>&, int, std::vector<std::vector<long long int> >&, int)'
    6 | long long helper(vector<int>& v, vector<int>& w, int W, vector<vector<long long>>& memo, int index){
      |                                                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~