Submission #1102783

#	Time	Username	Problem	Language	Result	Execution time	Memory
1102783		epicci23	The short shank; Redemption (BOI21_prison)	C++17	100 / 100	303 ms	174784 KiB

prison

#include "bits/stdc++.h"
//#define int long long
#define all(v) v.begin() , v.end()
#define sz(a) (int)a.size()
using namespace std;


const int N = 2e6 + 5;
const int INF = 1e9;
const int LOG = 20;
int n,d,t;
vector<vector<int>> v;
vector<int> ar,par,mark,vis,dp,ptr;

void dfs(int c){
  if(vis[c]) return;
  vis[c]=1;
  ptr[c]=c;
  dp[c]=0;
  for(int x:v[c]){
    dfs(x);
    if(dp[x]>=dp[c]){
      dp[c]=dp[x]+1;
      ptr[c]=ptr[x];
    }
  }
}

void _(){
  cin >> n >> d >> t;
  v.resize(n+5),ar.resize(n+5),par.assign(n+5,-1);
  mark.assign(n+5,0),vis.assign(n+5,0);
  dp.resize(n+5);ptr.resize(n+5);
  for(int i=1;i<=n;i++) cin >> ar[i];
  stack<int> s,s2;
  int hm = INF,lol=0;
  for(int i=1;i<=n;i++){
   hm++;
   hm=min(hm,ar[i]);
   if(hm<=t && ar[i]>t){
    mark[i]=1;
    while(!s2.empty() && ar[s2.top()]+i-s2.top()>t) s2.pop();
    while(!s.empty() && s.top()+t-ar[s.top()]<i && (s2.empty() ? 0 : s2.top())<s.top()){
      par[s.top()]=i;
      v[i].push_back(s.top());
      s.pop();
    }
    s.push(i);
   }
   else s2.push(i);
  }
  
  priority_queue<array<int,2>> pq;
  vector<int> use(n+5,0),kill(n+5,0);

  for(int i=1;i<=n;i++){
    if(!mark[i]) continue;
    dfs(i);
    if(par[i]==-1) pq.push({dp[i],i});
  }
  
  while(d-- && !pq.empty()){
    int c = pq.top()[1];
    pq.pop();
    use[ptr[c]]=1;
    int u=ptr[c];
    while(u!=c){
      kill[u]=1;
      for(int x:v[u]) if(!kill[x]) pq.push({dp[x],x});
      u=par[u];
    }
    for(int x:v[u]) if(!kill[x]) pq.push({dp[x],x});
  }

  int ans=0;hm=INF;
  for(int i=1;i<=n;i++){
    hm++;
    if(use[i]) hm=ar[i];
    else hm=min(hm,ar[i]);
    if(hm<=t) ans++;
  }

  cout << ans << '\n';
}

int32_t main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tc=1;//cin >> tc;
  while(tc--) _();
  return 0;
}

Compilation message (stderr)

prison.cpp: In function 'void _()':
prison.cpp:36:16: warning: unused variable 'lol' [-Wunused-variable]
   36 |   int hm = INF,lol=0;
      |                ^~~

• Subtask 1: 15 / 15
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 10 / 10
• Subtask 5: 25 / 25
• Subtask 6: 20 / 20