Language: C++

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


ll N, X;
ll x[200002];
unordered_map<tuple<int, int, int>, ll> memo;

ll dfs(int p, int p_g, int prev_size) {
	if (p == N) return 0;
	auto key = make_tuple(p, p_g, prev_size);
	if (memo.find(key) != memo.end()) memo[key];
	ll ret = 1LL << 60;

	int i = p;
	ll total_g = 0;
	for(int s=1;s<=prev_size && p+s <= N;s++) {
		while(i < p + s) {
			if(p_g == 1) {
				total_g += X + 4LL * x[i] + x[i];
			}else {
				ll lp_g = p_g;
				total_g += ((lp_g + 1) * (lp_g + 1) - lp_g * lp_g) * x[i];
			}
			i++;
		}
		ret = min(ret, total_g + dfs(p + s, p_g + 1, s));
	}
	memo[key] = ret;

	return ret;
}

int main() {
	cin >> N >> X;

	for(int i=0;i<N;i++) {
		cin >> x[i];
	}
	reverse(x, x + N);
	cout << N * X + dfs(0, 1, N) << endl;

	return 0;
}


Compiler output:
a.cc:8:41: error: use of deleted function 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map() [with _Key = std::tuple<int, int, int>; _Tp = long long int; _Hash = std::hash<std::tuple<int, int, int> >; _Pred = std::equal_to<std::tuple<int, int, int> >; _Alloc = std::allocator<std::pair<const std::tuple<int, int, int>, long long int> >]'
    8 | unordered_map<tuple<int, int, int>, ll> memo;
      |                                         ^~~~
In file included from /usr/include/c++/14/unordered_map:41,
                 from /usr/include/c++/14/functional:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/unordered_map.h:148:7: note: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map() [with _Key = std::tuple<int, int, int>; _Tp = long long int; _Hash = std::hash<std::tuple<int, int, int> >; _Pred = std::equal_to<std::tuple<int, int, int> >; _Alloc = std::allocator<std::pair<const std::tuple<int, int, int>, long long int> >]' is implicitly deleted because the default definition would be ill-formed:
  148 |       unordered_map() = default;
      |       ^~~~~~~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:148:7: error: use of deleted function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_Hashtable() [with _Key = std::tuple<int, int, int>; _Value = std::pair<const std::tuple<int, int, int>, long long int>; _Alloc = std::allocator<std::pair<const std::tuple<int, int, int>, long long int> >; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::tuple<int, int, int> >; _Hash = std::hash<std::tuple<int, int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, false, true>]'
In file included from /usr/include/c++/14/bits/unordered_map.h:33:
/usr/include/c++/14/bits/hashtable.h:539:7: note: 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_Hashtable() [with _Key = std::tuple<int, int, int>; _Value = std::pair<const std::tuple<int, int, int>, long long int>; _Alloc = std::allocator<std::pair<const std::tuple<int, int, int>, long long int> >; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::tuple<int, int, int> >; _Hash = std::hash<std::tuple<int, int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, false, true>]' is implicitly deleted because the default definition would be ill-formed:
  539 |       _Hashtable() = default;
      |       ^~~~~~~~~~
/usr/include/c++/14/bits/hashtable.h:539:7: error: use of deleted function 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _Traits>::_Hashtable_base() [with _Key = std::tuple<int, int, int>; _Value = std::pair<const std::tuple<int, int, int>, long long int>; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::tuple<int, int, int> >; _Hash = std::hash<std::tuple<int, int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _Traits = std::__detail::_Hashtable_traits<true, false, true>]'
In file included from /usr/include/c++/14/bits/hashtable.h:35:
/usr/include/c++/14/bits/hashtable_policy.h:1731:7: note: 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _Traits>::_Hashtable_base() [with _Key = std::tuple<int, int, int>; _Value = std::pair<const std::tuple<int, int, int>, long long int>; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::tuple<int, int, int> >; _Hash = std::hash<std::tuple<int, int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _Traits = std::__detail::_Hashtable_traits<true, false, true>]' is implicitly deleted because the default definition would be ill-formed:
 1731 |       _Hashtable_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1731:7: error: use of deleted function 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::_Hash_code_base() [with _Key = std::tuple<int, int, int>; _Value = std::pair<const std::tuple<int, int, int>, long long int>; _ExtractKey = std::__detail::_Select1st; _Hash = std::hash<std::tuple<int, int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; bool __cache_hash_code = true]'
/usr/include/c++/14/bits/hashtable_policy.h: In instantiation of 'std::__detail::_Hashtable_ebo_helper<_Nm, _Tp, true>::_Hashtable_ebo_helper() [with int _Nm = 1; _Tp = std::hash<std::tuple<int, int, int> >]':
/usr/include/c++/14/bits/hashtable_policy.h:1328:7:   required from here
 1328 |       _Hash_code_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1245:49: error: use of deleted function 'std::hash<std::tuple<int, int, int> >::hash()'
 1245 |       _Hashtable_ebo_helper() noexcept(noexcept(_Tp())) : _Tp() { }
      |                                                 ^~~~~
In file included from /usr/include/c++/14/string_view:50,
                 from /usr/include/c++/14/bits/basic_string.h:47,
                 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/functional_hash.h:102:12: note: 'std::hash<std::tuple<int, int, int> >::hash()' is implicitly deleted because the default definition would be ill-formed:
  102 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/14/bits/functional_hash.h:102:12: error: no matching function for call to 'std::__hash_enum<std::tuple<int, int, int>, false>::__hash_enum()'
/usr/include/c++/14/bits/functional_hash.h:83:7: note: candidate: 'std::__hash_enum<_Tp, <anonymous> >::__hash_enum(std::__hash_enum<_Tp, <anonymous> >&&) [with _Tp = std::tuple<int, int, int>; bool <anonymous> = false]'
   83 |       __hash_enum(__hash_enum&&);
      |       ^~~~~~~~~~~
/usr/include/c++/14/bits/functional_hash.h:83:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/functional_hash.h:102:12: error: 'std::__hash_enum<_Tp, <anonymous> >::~__hash_enum() [with _Tp = std::tuple<int, int, int>; bool <anonymous> = false]' is private within this context
  102 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/14/bits/functional_hash.h:84:7: note: declared private here
   84 |       ~__hash_enum();
      |       ^
/usr/include/c++/14/bits/hashtable_policy.h:1245:49: note: use '-fdiagnostics-all-candidates' to display considered candidates
 1245 |       _Hashtable_ebo_helper() noexcept(noexcept(_Tp())) : _Tp() { }
      |                                                 ^~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1328:7: note: 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::_Hash_code_base() [with _Key = std::tuple<int, int, int>; _Value = std::pair<const std::tuple<int, int, int>, long long int>; _ExtractKey = std::__detail::_Select1st; _Hash = std::hash<std::tuple<int, int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; bool __cache_hash_code = true]' is implicitly deleted because the default definition would be ill-formed:
 1328 |       _Hash_code_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1328:7: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::tuple<int, int, int> >, true>::~_Hashtable_ebo_helper()'
/usr/include/c++/14/bits/hashtable_policy.h:1242:12: note: 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::tuple<int, int, int> >, true>::~_Hashtable_ebo_helper()' is implicitly deleted because the default definition would be ill-formed:
 1242 |     struct _Hashtable_ebo_helper<_Nm, _Tp, true>
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1242:12: error: use of deleted function 'std::hash<std::tuple<int, int, int> >::~hash()'
/usr/include/c++/14/bits/functional_hash.h:102:12: note: 'std::hash<std::tuple<int, int, int> >::~hash()' is implicitly deleted because the default definition would be ill-formed:
  102 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/14/bits/functional_hash.h:102:12: error: 'std::__hash_enum<_Tp, <anonymous> >::~__hash_enum() [with _Tp = std::tuple<int, int, int>; bool <anonymous> = false]' is private within this context
/usr/include/c++/14/bits/functional_hash.h:84:7: note: declared private here
   84 |       ~__hash_enum();
      |       ^
/usr/include/c++/14/bits/hashtable_policy.h:1731:7: note: use '-fdiagnostics-all-candidates' to display considered candidates
 1731 |       _Hashtable_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1731:7: error: use of deleted function 'std::__detail::_Hash_code_base<std::tuple<int, int, int>, std::pair<const std::tuple<int, int, int>, long long int>, std::__detail::_Select1st, std::hash<std::tuple<int, int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()'
/usr/include/c++/14/bits/hashtable_policy.h:1306:12: note: 'std::__detail::_Hash_code_base<std::tuple<int, int, int>, std::pair<const std::tuple<int, int, int>, long long int>, std::__detail::_Select1st, std::hash<std::tuple<int, int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()' is implicitly deleted because the default definition would be ill-formed:
 1306 |     struct _Hash_code_base
      |            ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1306:12: error: use of delete