Submission #1190918

#	Time	Username	Problem	Language	Result	Execution time	Memory
1190918		DanielPr8	The short shank; Redemption (BOI21_prison)	C++20	100 / 100	345 ms	282128 KiB

prison

#include <bits/stdc++.h>
using namespace std;
using ll = int;
using vll = vector<ll>;
using vvl = vector<vll>;
using pll = pair<ll,ll>;
using vpl = vector<pll>;
using vvp = vector<vpl>;

#define f first
#define s second
#define pb push_back
#define all(v) v.begin(),v.end()
vvl g;
vll vis, dep, bes, pr;
void dfs(ll cur){
    bes[cur]=cur;
    for(ll i:g[cur]){
        dep[i]=dep[cur]+1;
        pr[i]=cur;
        dfs(i);
        if(dep[bes[i]]>dep[bes[cur]])bes[cur]=bes[i];
    }
}
ll m = 0;
void ear(priority_queue<pll>& pq, ll i){
    if(vis[i]==1)return;
    m++;
    vis[i]=1;
    for(ll j:g[i]){
        if(!vis[j]){
            pq.push({dep[bes[j]]-dep[j],j});
        }
    }
    if(pr[i]!=-1)ear(pq, pr[i]);
}
int main(){
    ios_base::sync_with_stdio(0);cin.tie(NULL);
    ll n, d, t;
    cin >> n >> d >> t;
    vll tm(n), ls(n);
    stack<pll> w;
    w.push({-1e9, -1});
    for(ll i = 0; i < n; ++i){
        cin >> tm[i];
        w.push({tm[i], i});
        while(w.top().f+i-w.top().s>t){
            w.pop();
        }
        ls[i]=w.top().s;
        if(ls[i]==-1)m++;
    }
    pr = vll(n,-1);
    stack<pll> q;
    g = vvl(n);
    vis=dep=bes=vll(n);
    vll lon;
    priority_queue<pll> pq;
    for(ll i = n-1; i >= 0; --i){
        if(ls[i]==i || ls[i]==-1)continue;
        while(!q.empty()){
            if(q.top().f>=i)q.pop();
            else break;
        }
        if(q.empty()){lon.pb(i);q.push({ls[i], i});continue;}
        g[q.top().s].pb(i);
        q.push({ls[i], i});
    }
    for(ll i: lon){
        dfs(i);
        pq.push({dep[bes[i]], i});
    }
    while(d-- && !pq.empty()){
        auto [a,b] = pq.top();
        pq.pop();
        ear(pq, bes[b]);
    }
    cout << n-m;
}

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