Language: C++

#include <unordered_map> 
#include <iostream>
#include <vector>
#define INF -(1 << 30)
using namespace std;
#define P pair<long long, int> 

unordered_map<P, int> mp;
int Q[60][4];
int n, m, q;

long long getCode(vector<int>& v){
    long long ret = 0;
    for( int i = 0; i < v.size(); i++ ){
        ret = ret * (long long)(m + 1) + ((v[i] == -1) ? 0 : v[i]);
        //cout << "HERE " << v[i] << ' ' << ret << ' ' << ret * (m + 1) << endl;
    }
    return ret;
}

bool isSorted(vector<int>& v ){
    int last = -1;
    for( int i = 0; i < v.size(); i++ )
        if(v[i] != -1){
            if(v[i] < last)
                return false;
            last = v[i];
        }
    return true;
}

int bt( vector<int>& v, int idx  ){
     if(!isSorted(v)){
        return INF;
    }
    if( idx == q )
        return 0;
    /*for( int i = 0; i < v.size(); i++ )
        cout << v[i] << ' ';
    cout << endl;
    cout << idx << ' ' << getCode(v) << endl << endl;;
    */
    if(mp.count(P(getCode(v), idx)))
        return mp[P(getCode(v), idx)];
    int ret = bt(v, idx + 1);
    if( v[Q[idx][0]] == -1 && v[Q[idx][1]] == -1 ){
        for( int i = Q[idx][2] + 1; i <= m; i++ ){
            v[Q[idx][1]] = i, v[Q[idx][0]] = i - Q[idx][2];
            ret = max(ret, Q[idx][3] + bt(v, idx + 1));
            v[Q[idx][1]] = -1, v[Q[idx][0]] = -1;
        }
    }
    else
        if( v[Q[idx][0]] == -1 && v[Q[idx][1]] != -1  ){
            if(v[Q[idx][1]] > Q[idx][2]){
                v[Q[idx][0]] = v[Q[idx][1]] - Q[idx][2];
                ret = max(ret, Q[idx][3] + bt(v, idx + 1));
                v[Q[idx][0]] = -1;
            }
        }
    else
        if( v[Q[idx][0]] != -1 && v[Q[idx][1]] == -1  ){
            if(v[Q[idx][0]] + Q[idx][2] <= m ){
                v[Q[idx][1]] = v[Q[idx][0]] + Q[idx][2];
                ret = max(ret, Q[idx][3] + bt(v, idx + 1));
                v[Q[idx][1]] = -1; 
            }
        }
    else{
        if(v[Q[idx][1]] - v[Q[idx][0]] == Q[idx][2])
            ret = max(ret, Q[idx][3] + bt(v, idx + 1));
    }
    return mp[P(getCode(v), idx)] = ret;
}

int main()
{
    
    cin >> n >> m >> q;
    for( int i = 0; i < q; i++ ){
        for( int j = 0; j < 4; j++ )
            cin >> Q[i][j];
        Q[i][0]--, Q[i][1] --;
    }
    vector<int> v(n, -1);
    cout << bt(v, 0) << endl;
    return 0;
}

Compiler output:
a.cc:8:23: error: use of deleted function 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map() [with _Key = std::pair<long long int, int>; _Tp = int; _Hash = std::hash<std::pair<long long int, int> >; _Pred = std::equal_to<std::pair<long long int, int> >; _Alloc = std::allocator<std::pair<const std::pair<long long int, int>, int> >]'
    8 | unordered_map<P, int> mp;
      |                       ^~
In file included from /usr/include/c++/14/unordered_map:41,
                 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::pair<long long int, int>; _Tp = int; _Hash = std::hash<std::pair<long long int, int> >; _Pred = std::equal_to<std::pair<long long int, int> >; _Alloc = std::allocator<std::pair<const std::pair<long long int, int>, 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::pair<long long int, int>; _Value = std::pair<const std::pair<long long int, int>, int>; _Alloc = std::allocator<std::pair<const std::pair<long long int, int>, int> >; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::pair<long long int, int> >; _Hash = std::hash<std::pair<long long 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::pair<long long int, int>; _Value = std::pair<const std::pair<long long int, int>, int>; _Alloc = std::allocator<std::pair<const std::pair<long long int, int>, int> >; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::pair<long long int, int> >; _Hash = std::hash<std::pair<long long 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::pair<long long int, int>; _Value = std::pair<const std::pair<long long int, int>, int>; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::pair<long long int, int> >; _Hash = std::hash<std::pair<long long 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::pair<long long int, int>; _Value = std::pair<const std::pair<long long int, int>, int>; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::pair<long long int, int> >; _Hash = std::hash<std::pair<long long 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::pair<long long int, int>; _Value = std::pair<const std::pair<long long int, int>, int>; _ExtractKey = std::__detail::_Select1st; _Hash = std::hash<std::pair<long long 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::pair<long long 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::pair<long long int, int> >::hash()'
 1245 |       _Hashtable_ebo_helper() noexcept(noexcept(_Tp())) : _Tp() { }
      |                                                 ^~~~~
In file included from /usr/include/c++/14/bits/hashtable_policy.h:35:
/usr/include/c++/14/bits/functional_hash.h:102:12: note: 'std::hash<std::pair<long long 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::pair<long long 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::pair<long long 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::pair<long long 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::pair<long long int, int>; _Value = std::pair<const std::pair<long long int, int>, int>; _ExtractKey = std::__detail::_Select1st; _Hash = std::hash<std::pair<long long 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::pair<long long 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::pair<long long 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::pair<long long int, int> >::~hash()'
/usr/include/c++/14/bits/functional_hash.h:102:12: note: 'std::hash<std::pair<long long 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::pair<long long 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::pair<long long int, int>, std::pair<const std::pair<long long int, int>, int>, std::__detail::_Select1st, std::hash<std::pair<long long 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::pair<long long int, int>, std::pair<const std::pair<long long int, int>, int>, std::__detail::_Select1st, std::hash<std::pair<long long 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 deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<long long int, int> >, true>::~_Hashtable_ebo_helper()'
/usr/include/c++/14/bits/hashtable.h:539:7: note: use '-fdiagnostics-all-candidates' to display considered candidates
  539 |       _Hashtable() = default;
      |       ^~~~~~~~~~
/usr/include/c++/14/bits/hashtable.h:539:7: er