Submission #824125

#	Time	Username	Problem	Language	Result	Execution time	Memory
824125		alvingogo	The short shank; Redemption (BOI21_prison)	C++14	100 / 100	364 ms	272808 KiB

prison

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define AquA cin.tie(0);ios_base::sync_with_stdio(0);
#define fs first
#define sc second
#define p_q priority_queue
#define int long long
using namespace std;

struct no{
    vector<int> ch;
    int dep=-1,dp=0;
};
vector<no> g;
void dfs(int r,int f){
    g[r].dep=g[f].dep+1;
    g[r].dp=g[r].dep;
    for(auto h:g[r].ch){
        dfs(h,r);
        g[r].dp=max(g[r].dp,g[h].dp);
    }
}
vector<int> z;
void dfs2(int r,int f,int y){
    pair<int,int> mx(-1,-1);
    for(auto h:g[r].ch){
        mx=max(mx,{g[h].dp,h});
    }
    for(auto h:g[r].ch){
        if(mx.sc==h){
            dfs2(h,r,y+1);
        }
        else{
            dfs2(h,r,1);
        }
    }
    if(mx.sc==-1){
        z.push_back(y);
    }
}
signed main(){
    AquA;
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    int n,d,t;
    cin >> n >> d >> t;
    g.resize(n+1);
    vector<int> v(n),fl(n);
    int x=t;
    for(int i=0;i<n;i++){
        cin >> v[i];
        x=min(x+1,v[i]);
        if(x>t){
            fl[i]=1;
        }
    }
    int rt=n;
    int rn=2e9;
    vector<int> s;
    s.push_back(n);
    int ans=0;
    for(int i=n-1;i>=0;i--){
        if(fl[i]){
            s.clear();
            s.push_back(n);
            rn=2e9;
            continue;
        }
        if(v[i]<=t){
            rn=min(rn,v[i]-i);
            ans++;
        }
        else{
            while(s.back()!=n && t-s.back()>=rn){
                s.pop_back();
            }
            g[s.back()].ch.push_back(i);
            s.push_back(i);
            rn=2e9;
        }
    }
    dfs(rt,rt);
    dfs2(rt,rt,0);
    sort(z.begin(),z.end(),greater<int>());
    d=min(d,(int)z.size());
    for(int i=d;i<z.size();i++){
        ans+=z[i];
    }
    cout << ans << "\n";
    return 0;
}

Compilation message (stderr)

prison.cpp: In function 'int main()':
prison.cpp:86:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |     for(int i=d;i<z.size();i++){
      |                 ~^~~~~~~~~

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