Submission #668139

#	Time	Username	Problem	Language	Result	Execution time	Memory
668139		definitelynotmee	Table Tennis (info1cup20_tabletennis)	C++98	Compilation error	0 ms	0 KiB

tabletennis

#include<bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define all(x) x.begin(), x.end()
using ll = long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
template<typename T>
using matrix = vector<vector<T>>;

struct hashzao{
    int operator()(int i){
        return i^981723478;
    }
};


int main(){
    cin.tie(0)->sync_with_stdio(0);

    int n, k;
    cin >> n >> k;

    vector<int> v(n+k);
    for(int i = 0; i < n+k; i++)
        cin >> v[i];

    unordered_map<int,int,hashzao> sums;

    int minmid = max(0,(n+k)/2-k/2-3), maxmid = min(n+k-1,(n+k)/2+k/2+3);

    for(int offset = -k; offset <= k; offset++){
        for(int i = 0; i < n+k; i++){
            int y = n+k-i-1;
            y+=offset;
            if(y >= 0 && y < n+k)
                sums[v[i]+v[y]]++;
        }
    }

    auto findans =[&](int sum){
        int p1 = 0, p2 = n+k-1;
        vector<int> resp;

        while(p1 < p2){
            if(v[p1] + v[p2] > sum){
                p2--;
                continue;
            }
            if(v[p1] + v[p2] < sum){
                p1++;
                continue;
            }
            resp.push_back(v[p1]), resp.push_back(v[p2]);
            p1++, p2--;
        }

        sort(all(resp));
        for(int i = 0; i < n; i++)
            cout << resp[i] << ' ';
        cout << '\n';
    };

    // for(pii i : sums)
    //     cout << i.ff << ' ' << i.ss << '\n';

    for(pii i : sums){
        if(i.ss < n)
            continue;
        int sum = i.ff;
        int resp = 0;
        int p1 = 0, p2 = n+k-1;

        while(p1 < p2){
            if(v[p1] + v[p2] > sum){
                p2--;
                continue;
            }
            if(v[p1] + v[p2] < sum){
                p1++;
                continue;
            }

            p1++, p2--;
            resp++;
        }
        //cout << sum << ' ' << resp << '\n';
        if(resp >= n/2){
            findans(sum);
            return 0;
        }
    }
    //exit(1);

}

Compilation message (stderr)

tabletennis.cpp: In function 'int main()':
tabletennis.cpp:31:9: warning: unused variable 'minmid' [-Wunused-variable]
   31 |     int minmid = max(0,(n+k)/2-k/2-3), maxmid = min(n+k-1,(n+k)/2+k/2+3);
      |         ^~~~~~
tabletennis.cpp:31:40: warning: unused variable 'maxmid' [-Wunused-variable]
   31 |     int minmid = max(0,(n+k)/2-k/2-3), maxmid = min(n+k-1,(n+k)/2+k/2+3);
      |                                        ^~~~~~
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:117,
                 from tabletennis.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h: In instantiation of 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::__hash_code std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::_M_hash_code(const _Key&) const [with _Key = int; _Value = std::pair<const int, int>; _ExtractKey = std::__detail::_Select1st; _H1 = hashzao; _H2 = std::__detail::_Mod_range_hashing; std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::__hash_code = long unsigned int]':
/usr/include/c++/10/bits/hashtable_policy.h:734:45:   required from 'std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::mapped_type& std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::operator[](std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::key_type&&) [with _Key = int; _Pair = std::pair<const int, int>; _Alloc = std::allocator<std::pair<const int, int> >; _Equal = std::equal_to<int>; _H1 = hashzao; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, false, true>; std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::mapped_type = int; std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::key_type = int]'
/usr/include/c++/10/bits/unordered_map.h:988:20:   required from 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::mapped_type& std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::key_type&&) [with _Key = int; _Tp = int; _Hash = hashzao; _Pred = std::equal_to<int>; _Alloc = std::allocator<std::pair<const int, int> >; std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::mapped_type = int; std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::key_type = int]'
tabletennis.cpp:38:31:   required from here
/usr/include/c++/10/bits/hashtable_policy.h:1377:16: error: static assertion failed: hash function must be invocable with an argument of key type
 1377 |  static_assert(__is_invocable<const _H1&, const _Key&>{},
      |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1379:16: error: no match for call to '(const hashzao) (const int&)'
 1379 |  return _M_h1()(__k);
      |         ~~~~~~~^~~~~
tabletennis.cpp:13:9: note: candidate: 'int hashzao::operator()(int)' (near match)
   13 |     int operator()(int i){
      |         ^~~~~~~~
tabletennis.cpp:13:9: note:   passing 'const hashzao*' as 'this' argument discards qualifiers