Submission #999447

#	Time	Username	Problem	Language	Result	Execution time	Memory
999447		AdamGS	Cultivation (JOI17_cultivation)	C++17	35 / 100	2056 ms	604 KiB

cultivation

#include<bits/stdc++.h>
using namespace std;
typedef long double ld;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const ll INF=2e9+7;
const int LIM=307;
pair<ll,ll>T[LIM];
ll R, C, n;
vector<pair<ll,ll>>Ci, Di, Ei;
ll solveab(ll a, ll b) {
  ll c=0, d=0, cpd=0, lst=1;
  ll po=0, ko=Ci.size()-1;
  while(po<ko) {
    ll sr=(po+ko)/2;
    if(Ci[sr].st>b) po=sr+1; else ko=sr;
  }
  c=Ci[po].nd;
  po=0; ko=Di.size()-1;
  while(po<ko) {
    ll sr=(po+ko)/2;
    if(Di[sr].st>b) po=sr+1; else ko=sr;
  }
  d=Di[po].nd;
  po=0; ko=(int)Ei.size()-1;
  while(po<ko) {
    ll sr=(po+ko)/2;
    if(Ei[sr].st<b) po=sr+1; else ko=sr;
  }
  if(Ei.size()>0 && Ei[po].st>=b) cpd=max(Ei[po].nd, 0ll);
  set<pair<ll,ll>>A;
  multiset<ll>B;
  vector<pair<ll,ll>>V;
  vector<ll>odw(n);
  rep(i, n) V.pb({max(1ll, T[i].st-a), i});
  rep(i, n) V.pb({min(R+1, T[i].st+b+1), i});
  sort(all(V));
  for(auto i : V) {
    if(i.st!=lst) {
      if(B.size()) {
        auto it=B.end(); --it;
        ll p=*it;
        cpd=max(cpd, p);
      }
      lst=i.st;
    }
    if(!odw[i.nd]) {
      odw[i.nd]=1;
      if(A.size()) {
        ll lewo=0, prawo=C+1;
        auto it=A.lower_bound({T[i.nd].nd, i.nd});
        if(it!=A.end()) {
          auto p=*it;
          prawo=p.st;
        }
        if(it!=A.begin()) {
          --it;
          auto p=*it;
          lewo=p.st;
        }
        if(lewo!=0 && prawo!=C+1) B.erase(B.find(prawo-lewo-1));
        if(lewo!=0) B.insert(T[i.nd].nd-lewo-1);
        if(prawo!=C+1) B.insert(prawo-T[i.nd].nd-1);
      }
      A.insert({T[i.nd].nd, i.nd});
    } else {
      A.erase({T[i.nd].nd, i.nd});
      if(A.size()) {
        ll lewo=0, prawo=C+1;
        auto it=A.lower_bound({T[i.nd].nd, i.nd});
        if(it!=A.end()) {
          auto p=*it;
          prawo=p.st;
        }
        if(it!=A.begin()) {
          --it;
          auto p=*it;
          lewo=p.st;
        }
        if(lewo!=0 && prawo!=C+1) B.insert(prawo-lewo-1);
        if(lewo!=0) B.erase(B.find(T[i.nd].nd-lewo-1));
        if(prawo!=C+1) B.erase(B.find(prawo-T[i.nd].nd-1));
      }
    }
  }
  return a+b+max(c+d, cpd);
}
ll solvea(ll a) {
  Ci.clear(); Di.clear(); Ei.clear();
  vector<pair<ll,ll>>P;
  rep(i, n) P.pb({T[i].nd, i});
  sort(all(P));
  rep(i, n) {
    vector<pair<ll,ll>>Q;
    rep(j, i+1) Q.pb({max(1ll, T[P[j].nd].st-a), T[P[j].nd].st});
    sort(all(Q));
    ll ma=1, mi=0;
    for(auto j : Q) {
      mi=max(mi, j.st-ma-1);
      ma=max(ma, j.nd);
    }
    mi=max(mi, R-ma);
    if(Q[0].st!=1) mi=INF;
    Ci.pb({mi, P[i].st-1});
  }
  rep(i, n) {
    vector<pair<ll,ll>>Q;
    rep(j, i+1) Q.pb({max(1ll, T[P[n-j-1].nd].st-a), T[P[n-j-1].nd].st});
    sort(all(Q));
    ll ma=1, mi=0;
    for(auto j : Q) {
      mi=max(mi, j.st-ma-1);
      ma=max(ma, j.nd);
    }
    mi=max(mi, R-ma);
    if(Q[0].st!=1) mi=INF;
    Di.pb({mi, C-P[n-i-1].st});
  }
  rep(xd, 2) {
    rep(j, n) rep(i, j) {
      if(T[P[i].nd].st<=T[P[j].nd].st) {
        ll mi=R+1, ma=0;
        bool czy=false;
        for(int l=i+1; l<j; ++l) {
          if(T[P[l].nd].st>=T[P[j].nd].st) mi=min(mi, T[P[l].nd].st-a);
          if(T[P[l].nd].st<=T[P[i].nd].st) ma=max(ma, T[P[l].nd].st);
          if(T[P[l].nd].st>=T[P[i].nd].st && T[P[l].nd].st<=T[P[j].nd].st) czy=true;
        }
        if(czy || mi<=0) Ei.pb({-1, abs(P[i].st-P[j].st)-1});
        else if(mi==10*INF || ma==0) Ei.pb({10*INF, abs(P[i].st-P[j].st)-1});
        else Ei.pb({mi-ma-2, abs(P[i].st-P[j].st)-1});
      }
    }
    reverse(all(P));
  }
  sort(all(Ei));
  for(int i=(int)Ei.size()-2; i>=0; --i) Ei[i].nd=max(Ei[i].nd, Ei[i+1].nd);
  vector<ll>A;
  rep(i, n) A.pb(T[i].st);
  sort(all(A));
  ll b=R-A[n-1], apb=0;
  rep(i, n-1) apb=max(apb, A[i+1]-A[i]-1);
  ll ans=INF;
  rep(i, n) {
    ll x=R-T[i].st;
    if(x>=b && a+x>=apb) ans=min(ans, solveab(a, x));
  }
  rep(i, n) rep(j, i) {
    ll x=abs(T[i].st-T[j].st)-1;
    if(x==-1 || x<apb) continue;
    ll y=x-a;
    if(y>=b) ans=min(ans, solveab(a, y));
  }
  return ans;
}
ll solve() {
  ll ans=INF;
  rep(i, n) ans=min(ans, solvea(T[i].st-1));
  return ans;
}
int main() {
  ios_base::sync_with_stdio(0); cin.tie(0);
  cin >> R >> C >> n;
  rep(i, n) cin >> T[i].st >> T[i].nd;
  ll ans=INF;
  rep(i, 4) {
    ans=min(ans, solve());
    rep(j, n) T[j]={C-T[j].nd+1, T[j].st};
    swap(R, C);
  }
  cout << ans << '\n';
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 30 / 30
• Subtask 5: 0 / 20
• Subtask 6: 0 / 20