Submission #638682

#	Time	Username	Problem	Language	Result	Execution time	Memory
638682		Dec0Dedd	Table Tennis (info1cup20_tabletennis)	C++14	100 / 100	487 ms	45612 KiB

tabletennis

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
const int N = 2e5+10;
const int K = 400;
 
int a[N], n, k, sz;
gp_hash_table<int, bool> m;

int num(int s) {
   int res=0;
   for (int i=1; i<=sz; ++i) {
      if (2*a[i] == s || m.find(s-a[i]) == m.end()) continue;
      ++res;
   }
   return res;
}

vector<int> gen(int s) {
   vector<int> res; int p=0;
   for (int i=1; i<=sz; ++i) {
      if (2*a[i] == s || m.find(s-a[i]) == m.end()) continue;
      res.push_back(a[i]), res.push_back(s-a[i]);
      p+=2;
      if (p == n) break;
   }
   return res;
}
 
int main() {
 
   cin>>n>>k;
   sz=n+k;
   for (int i=1; i<=sz; ++i) cin>>a[i];
   for (int i=1; i<=sz; ++i) m[a[i]]=true;

   vector<int> x;

   if (sz <= 5*K) {
      bool ok=false;
      for (int i=1; i<=sz && !ok; ++i) {
         for (int j=i+1; j<=sz && !ok; ++j) {
            if (num(a[i]+a[j]) >= n) {
               x=gen(a[i]+a[j]);
               ok=true;
               break;
            }
         }
      }
   } else {
      gp_hash_table<int, int> cnt;

      for (int i=1; i<=2*k+1; ++i) {
         for (int j=n-k-1; j<=sz; ++j) ++cnt[a[i]+a[j]];
      }

      for (auto u : cnt) {
         if (u.second >= k) {
            if (num(u.first) >= n) {
               x=gen(u.first);
               break;
            }
         }
      }
   }

   sort(x.begin(), x.end());
   assert((int)x.size() >= n);
   for (auto u : x) cout<<u<<" ";
   cout<<"\n";
}

• Subtask 1: 11 / 11
• Subtask 2: 9 / 9
• Subtask 3: 14 / 14
• Subtask 4: 15 / 15
• Subtask 5: 9 / 9
• Subtask 6: 14 / 14
• Subtask 7: 15 / 15
• Subtask 8: 13 / 13