Submission #900145

#	Time	Username	Problem	Language	Result	Execution time	Memory
900145		cadmiumsky	Closing Time (IOI23_closing)	C++17	75 / 100	648 ms	69752 KiB

closing

#include <bits/stdc++.h>
#include "closing.h"
#define all(x) (x).begin(),(x).end()
using namespace std;
 
using ll = long long;
using ld = long double;
 
#define int ll
#define sz(x) ((int)(x).size())
 
using pii = pair<ll,ll>;
using tii = tuple<int,int,int>;
 
const int nmax = 3e3 + 5;
 
vector<pii> g[nmax];
 
vector<ll> dX, dY;
vector<int> occX;
 
vector<int> chain;
 
void dfs(int node, int f, vector<ll>& d, ll accum) {
  d[node] = accum;
  for(auto [x, c] : g[node])
    if(x != f)
      dfs(x, node, d, accum + c);
  
  return;
}
 
void findchain(int node, int f, int Y) {
  if(sz(chain) && chain.back() == Y) return;
  chain.emplace_back(node);
  for(auto [x, e] : g[node]) {
    if(x == f) continue;
    findchain(x, node, Y);
  }
  if(chain.back() == Y) return;
  chain.pop_back();
}
 
int disjointed(int n, ll K, int X, int Y) {
  priority_queue<pii, vector<pii>, greater<pii>> heap;
  
  vector<int> occY(n, 0);
  
  heap.emplace(0, Y);
  heap.emplace(0, X);
  
  int scorefromY = 0;
  
  while(!heap.empty()) {
    auto [C, node] = heap.top();
    K -= C;
    
    if(K < 0) break;
    
    heap.pop();
    occY[node] = 1;
    scorefromY++;
    
    for(auto [x, e] : g[node]) {
      if(occY[x]) continue;
      heap.emplace(C + e, x);
    }
  }
  
  return scorefromY;
} 

const ll inf = ((ll)1e18) + 5;

int X, Y;
 
namespace DP {
  
  int foutu[nmax];
  
  vector<ll> dp[nmax][2];
  int dim[nmax][2];
  
  void clear(int n) {
    for(int i = 0; i < n; i++) {
      dim[i][0] = dim[i][1] = 0;
      dp[i][0].clear();
      dp[i][1].clear();
      foutu[i] = 0;
    }
  }
  
  void convolute(vector<ll> a, vector<ll> b, vector<ll>& c) {
    c.resize(max(sz(c), sz(a) + sz(b) - 1), inf);
    //cerr << sz(a) << ' ' << sz(b) << ' ' << sz(c) << '\n';
    for(int i = 0; i < sz(a); i++)
      for(int j = 0; j < sz(b); j++)
        c[i + j] = min(c[i + j], a[i] + b[j]);
    return;
  }
  
  void getdp(int node, int f) { // vectori???
    dp[node][0].resize(2, inf);
    dp[node][1].resize(3, inf);
    dp[node][0][1] = min(dX[node], dY[node]);
    dp[node][1][2] = max(dX[node], dY[node]);
    
    //cerr << node << '\n';
    
    for(auto [x, e] : g[node]) {
      if(x == f) continue;
      getdp(x, node);
      foutu[node] |= foutu[x];
    }
    
    for(auto [x, e] : g[node]) {
      if(x == f) continue;
      
      vector<ll> tmp;
      
      if(!foutu[x])
        tmp = dp[node][0];
      convolute(dp[node][0], dp[x][0], tmp);
      
      dp[node][0] = move(tmp);
      
      tmp.clear();
      if(!foutu[x])
        tmp = dp[node][1];
      convolute(dp[node][1], dp[x][1], tmp);
      convolute(dp[node][1], dp[x][0], tmp);
      dp[node][1] = move(tmp);
    }
    
    //cerr << node << ":\n";
    //cerr << foutu[node] << '\n';
    //for(auto x : dp[node][0]) cerr << x << ' '; cerr << '\n';
    //for(auto x : dp[node][1]) cerr << x << ' '; cerr << '\n';
    //cerr << "---\n";
    
    foutu[node] = foutu[node] | (node == X || node == Y);
    
    return;
  }
  
  int getRestraint(int n, int root, ll K) {
    clear(n);
    //cerr << "\t\t\t" << root << '\n';
    getdp(root, root);
    //cerr << "! " << sz(dp[root][1]) << '\n';
    for(int i = sz(dp[root][1]) - 1; i >= 0; i--)
      if(dp[root][1][i] <= K) return i;
    return 0;
  }
}
 
#undef int
int max_score(int n, int _X, int _Y, long long K,
              std::vector<int> U, std::vector<int> V, std::vector<int> W) {
  X = _X;
  Y = _Y;
  #define int ll
  for(int i = 0; i < n; i++) g[i].clear();
  chain.clear();
  dX.clear();
  dY.clear();
  occX.clear();
  
  for(int i = 0; i < n - 1; i++)
    g[U[i]].emplace_back(V[i], W[i]),
    g[V[i]].emplace_back(U[i], W[i]);
    
  dX.resize(n);
  dY.resize(n);
  
  dfs(X, X, dX, 0);
  dfs(Y, Y, dY, 0);
  
  findchain(X, X, Y);

  int maxscore = disjointed(n, K, X, Y);
  
  int prv = X;
  for(auto x : chain) {
    if(dX[x] > dY[x]) { maxscore = max(maxscore, DP::getRestraint(n, prv, K)); break; }
    prv = x;
  }
  
  prv = Y;
  reverse(all(chain));
  for(auto x : chain) {
    if(dY[x] > dX[x]) { maxscore = max(maxscore, DP::getRestraint(n, prv, K)); break; }
    prv = x;
  }
  
  return maxscore;
}
#undef int

• Subtask 0: 0 / 0
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• Subtask 2: 9 / 9
• Subtask 3: 12 / 12
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