Submission #825447

#	Time	Username	Problem	Language	Result	Execution time	Memory
825447		ikaurov	Garden (JOI23_garden)	C++17	100 / 100	2744 ms	135656 KiB

garden

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define all(arr) (arr).begin(), (arr).end()
#define ll long long
#define ld long double
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define endl '\n'

int d;

int calc(int x){
  x %= d;
  if (x < 0) x += d;
  return x;
}

struct linkedlist{
  int n;
  int maxval;
  vector<int> nxt, prv, val;

  int calcdist(int i){
    if (nxt[i] > i) return val[nxt[i]] - val[i];
    else return val[nxt[i]] - val[i] + d;
  }

  linkedlist(){};
  linkedlist(vector<pair<int, int>>& a){
    n = sz(a);
    nxt.resize(n);
    prv.resize(n);
    val.resize(n);
    iota(all(nxt), 1);
    nxt[n - 1] = 0;
    iota(all(prv), -1);
    prv[0] = n - 1;
    for (int i = 0; i < n; i++) val[i] = a[i].fi;
    maxval = 0;
    for (int i = 0; i < n; i++){
      maxval = max(maxval, calcdist(i));
    }
  };

  void del(int idx){
    if (nxt[idx] == idx) return;
    nxt[prv[idx]] = nxt[idx];
    prv[nxt[idx]] = prv[idx];
    maxval = max(maxval, calcdist(prv[idx]));
  }

  void add(int idx, int nxtidx){
    int prvidx = prv[nxtidx];
    nxt[prvidx] = prv[nxtidx] = idx;
    prv[idx] = prvidx, nxt[idx] = nxtidx;
  }

  int get(){
    return maxval;
  }
};

signed main(){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  // cout.precision(20);
  int n, m;
  cin >> n >> m >> d;
  vector<int> x(n + m), y(n + m), nodeid(n + m);
  vector<bool> used(n);
  vector<pair<int, int>> sy(n + m);
  vector<int> cnt(d), preva(n + m);
  vector<vector<int>> nxtidx(d, vector<int>(d, -1)), gonext(n);
  for (int i = 0; i < n + m; i++){
    cin >> x[i] >> y[i];
    if (i < n) cnt[x[i]]++;
    sy[i] = {y[i], i};
    nxtidx[x[i]][y[i]] = i;
  }
  for (int val = 0; val < d; val++){
    int idx = 0;
    while (idx < d && nxtidx[idx][val] == -1) idx++;
    if (idx == d) continue;
    for (int i = calc(idx - 1), last = nxtidx[idx][val]; i != idx; i = calc(i - 1)){
      if (nxtidx[i][val] != -1) last = nxtidx[i][val];
      nxtidx[i][val] = last;
    }
  }
  sort(all(sy));
  linkedlist ls(sy);
  for (int i = 0; i < n + m; i++) nodeid[sy[i].se] = i;
  int startmaxval = ls.maxval;
  for (int i = n; i < n + m; i++) ls.del(nodeid[i]);
  sy.insert(sy.end(), all(sy));
  int lasta;
  for (auto [val, i] : sy){
    if (i < n) lasta = i;
    preva[i] = lasta;
  }
  int ans = 1e9;
  for (int start = 0; start < d; start++){
    vector<vector<int>> hasx(d);
    vector<int> usedvector;

    for (int val = 0; val < d; val++){
      int cur = nxtidx[start][val];
      if (cur == -1 || cur < n || nodeid[preva[cur]] > nodeid[cur]) continue;
      hasx[x[cur]].pb(cur);
      gonext[preva[cur]].pb(cur);
      if (used[preva[cur]]) continue;
      usedvector.pb(preva[cur]);
      used[preva[cur]] = 1;
    }

    for (int val = 0; val < d; val++){
      int cur = nxtidx[start][val];
      if (cur == -1 || cur < n || nodeid[preva[cur]] < nodeid[cur]) continue;
      hasx[x[cur]].pb(cur);
      gonext[preva[cur]].pb(cur);
      if (used[preva[cur]]) continue;
      usedvector.pb(preva[cur]);
      used[preva[cur]] = 1;
    }

    for (auto i : usedvector){
      int nextnode = ls.nxt[nodeid[i]];
      for (auto v : gonext[i]) ls.add(nodeid[v], nextnode);
    }

    ls.maxval = startmaxval;
    int acnt = n;
    for (int finish = calc(start - 1);; finish = calc(finish - 1)){
      if (acnt == 0){
        ans = min(ans, (d - calc(finish - start) - 1) * (d + 1 - ls.get()));
      }
      for (auto i : hasx[finish]){
        ls.del(nodeid[i]);
      }
      acnt -= cnt[finish];
      if (finish == start){
        ans = min(ans, d * (d + 1 - ls.get()));
        break;
      }
    }
    for (auto i : usedvector){
      used[i] = 0;
      gonext[i].clear();
    }
  }
  cout << ans << endl;
}

Compilation message (stderr)

garden.cpp: In function 'int main()':
garden.cpp:101:14: warning: 'lasta' may be used uninitialized in this function [-Wmaybe-uninitialized]
  101 |     preva[i] = lasta;

• Subtask 1: 15 / 15
• Subtask 2: 6 / 6
• Subtask 3: 8 / 8
• Subtask 4: 16 / 16
• Subtask 5: 30 / 30
• Subtask 6: 25 / 25