Language: C++

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int,int> p_int;
typedef pair<ll,ll> p_ll;
typedef tuple<ll,ll,ll> t3_ll;
int dx[] = {-1,0,1,0},dy[] = {0,1,0,-1};
int prime[] = {2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97};
const ll inf = 1000000007;

int main() {
	int n,W;
	cin >> n >> W;
	ll w[n],v[n];
	map<ll,ll> dp[n];
	for (int i = 0;i < n;i++) {
		cin >> w[i] >> v[i];
	}
	dp[0][0] = 0; dp[0][w[0]] = v[0];
	for (int i = 0;i < n-1;i++) {
		for (auto j = dp[i].begin();j != dp[i].end();j++) {
			dp[i+1][j->first] = max(dp[i+1][j->first],dp[i][j->first]);
			if (j+w[i+1] <= W) {
				dp[i+1][j->first+w[i+1]] = max(dp[i+1][j->first+w[i+1]],dp[i][j->first]+v[i->first+1]);
			}
		}
	}
	ll ans = 0;
	for (auto itr = dp[n-1].begin();itr != dp[n-1].end();itr++) {
		ans = max(ans,itr -> second);
	}
	cout << ans << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:24:30: error: no match for 'operator+' (operand types are 'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' and 'll' {aka 'long long int'})
   24 |                         if (j+w[i+1] <= W) {
      |                             ~^~~~~~~
      |                             |      |
      |                             |      ll {aka long long int}
      |                             std::_Rb_tree_iterator<std::pair<const long long int, 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:24:36: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'll' {aka 'long long int'}
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'll' {aka 'long long int'}
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
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:24:36: note:   'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   mismatched types 'const _CharT*' and 'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'll' {aka 'long long int'}
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   mismatched types 'const _CharT*' and 'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'll' {aka 'long long int'}
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/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:24:36: note:   'std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   24 |                         if (j+w[i+1] <= W) {
      |                                    ^
/usr/include/c++/14/bits/basic_string.h:3740:5: note: candidat