Submission #1074965

#	Time	Username	Problem	Language	Result	Execution time	Memory
1074965		bleahbleah	Closing Time (IOI23_closing)	C++17	100 / 100	203 ms	47168 KiB

closing

#include "closing.h"

#include <vector>
#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
using namespace std;

using ll = long long;
#define int ll

#define sz(x) ((int)(x).size())

using pii = pair<int,int>;

const int nmax = 2e5 + 5;

ll dx[nmax], dy[nmax];
int p[nmax];
vector<pii> g[nmax];

void filld(int node, int f, ll *d) {
   p[node] = f;
   for(auto [x, c] : g[node]) {
      if(x == f) continue;
      d[x] = d[node] + c;
      filld(x, node, d);
   }
   return;
}

int separate(int N, ll S) {
   vector<pii> s;
   for(int i = 0; i < N; i++) {
      s.emplace_back(i, 1);
      s.emplace_back(i, 2);
   }
   sort(all(s), [&](auto a, auto b) {
      return (a.second == 1? dx[a.first] : dy[a.first]) < (b.second == 1? dx[b.first] : dy[b.first]);
   });
   
   vector<int> occ(N, 0);
   int cnt = 0;
   for(auto [x, t] : s) {
      if(occ[x]) continue;
      auto C = (t == 1? dx[x] : dy[x]);
      if(S < C) break;
      S -= C;
      occ[x] = 1;
      cnt++;
   }
   
   return cnt;
}



signed max_score(signed N, signed X, signed Y, long long S, std::vector<signed> U, std::vector<signed> V, std::vector<signed> W) {
   for(int i = 0; i <= N; i++) g[i].clear();
   
   for(int i = 0; i < sz(U); i++) {
      g[U[i]].emplace_back(V[i], W[i]);
      g[V[i]].emplace_back(U[i], W[i]);
   }
   
   dx[X] = dy[Y] = 0;
   filld(X, X, dx);
   filld(Y, Y, dy);
   
   const int opt1 = separate(N, S);
   //cerr << opt1 << '\n';
   
   vector<int> onchain(N, 0);
   int t = X;
   while(t != Y) {
      onchain[t] = 1;
      t = p[t];
   }
   onchain[Y] = 1;
   
   vector<pair<ll, ll>> s;
   
   int opt2 = 0;
   for(int node = 0; node < N; node++) {
      //cerr << onchain[node] << ' ';
      if(onchain[node]) {
         int a = dx[node], b = dy[node];
         if(a > b) swap(a, b);
         S -= a;
         s.emplace_back(b - a, -1);
         opt2++;
      }
      else {
         int a = dx[node], b = dy[node];
         if(a > b) swap(a, b);
         b -= a;
         if(a <= b) {
            s.emplace_back(a, -1);
            s.emplace_back(b, -1);
         }
         else {
            s.emplace_back(a, b);
         }
      }
   }
   //cerr << '\n' << S << '\n';
   
   if(S < 0) return opt1;
   sort(all(s), [&](auto a, auto b) {
      auto C = (a.second == -1? 2 * a.first : a.first + a.second);
      auto D = (b.second == -1? 2 * b.first : b.first + b.second);
      return C < D;
   });
   
   //for(auto [a, b] : s) cerr << a << ' ' << b << '\n';
   

   auto simulate = [&s](int start, int S) {
      int cnt = 0;     
     for(int it = start; it < sz(s); it++) {
         auto [a, b] = s[it];
         if(b == -1) {
            if(a > S) break;
            S -= a;
            cnt++;
         }
         else {
            if(a + b > S) {
               for(int j = it + 1; j < sz(s); j++) 
                  a = min(a, s[j].first);
               if(S < a) break;
               cnt++;
               break;
            }
            else {
               S -= a + b;
               cnt += 2;
            }
         } 
      }
      return cnt;
   };
   
   vector<int> oper1;
   vector<pii> oper2;
   
   for(int it = 0; it < sz(s); it++) {
      auto [a, b] = s[it];
      if(b == -1) {
         if(a > S) break;
         S -= a;
         opt2++;
         oper1.emplace_back(a);
      }
      else {
         if(a + b > S) {
            int mx = simulate(it, S);
            if(sz(oper1)) {
               mx = max(simulate(it, S + oper1.back()) - 1, mx);
            }
            if(sz(oper2)) {
               auto [yi, er] = oper2.back();
               mx = max(simulate(it, S + er) - 1, mx);
               mx = max(simulate(it, S + yi + er) - 2, mx);
            }
            if(sz(oper1) && sz(oper2)) {
               auto [yi, er] = oper2.back();
               mx = max(simulate(it, S + yi + er + oper1.back()) - 3, mx);
            }
            opt2 += mx;
            break;
         }
         else {
            S -= a + b;
            oper2.emplace_back(a, b);
            opt2 += 2;
         }
      }
   }
   
   return max(opt1, opt2);
}

#undef int

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 12
• Subtask 4: 14 / 14
• Subtask 5: 9 / 9
• Subtask 6: 11 / 11
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 17 / 17