Submission #1025954

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025954		ttamx	The short shank; Redemption (BOI21_prison)	C++17	100 / 100	201 ms	53848 KiB

prison

#include<bits/stdc++.h>

using namespace std;

const int INF=INT_MAX/2;

const int N=2e6+5;

int n,d,t,m;
int a[N],pre[N],par[N];
int ans;
pair<int,int> range[N];
int dep[N],deep[N],cnt[N];
stack<pair<int,int>> s,st;

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n >> d >> t;
    for(int i=1;i<=n;i++)cin >> a[i];
    s.emplace(-INF,0);
    for(int i=1;i<=n;i++){
        int x=min(a[i],t)-i;
        while(s.top().first>x)s.pop();
        if(a[i]>t)pre[i]=s.top().second;
        else ans++;
        s.emplace(a[i]-i,i);
    }
    for(int i=1;i<=n;i++)if(pre[i])range[++m]={pre[i],i-1};
    ans+=m;
    for(int i=1;i<=m;i++){
        int x=range[i].first;
        while(!st.empty()&&st.top().first>=x){
            par[st.top().second]=i;
            st.pop();
        }
        st.emplace(x,i);
    }
    for(int u=1;u<=m;u++){
        cnt[dep[deep[u]]]--;
        dep[u]=dep[deep[u]]+1;
        cnt[dep[u]]++;
        if(dep[u]>dep[deep[par[u]]])deep[par[u]]=u;
    }
    for(int i=m;i>=1;i--)while(cnt[i]--&&d-->0)ans-=i;
    cout << ans;
}

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