Submission #824092

#	Time	Username	Problem	Language	Result	Execution time	Memory
824092		alvingogo	The short shank; Redemption (BOI21_prison)	C++14	0 / 100	1 ms	212 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;
};
vector<no> g;
int d;
void dfs(int r,int f){
    g[r].dep=g[f].dep+1;
    for(auto h:g[r].ch){
        if(h!=f){
            dfs(h,r);
        }
    }
}
vector<int> z;
void dfs2(int r,int f,int y){
    pair<int,int> mx(-1,-1);
    for(auto h:g[r].ch){
        if(h!=f){
            mx=max(mx,{g[h].dep,h});
        }
    }
    for(auto h:g[r].ch){
        if(h!=f){
            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;
    int n,t;
    cin >> n >> d >> t;
    g.resize(n);
    vector<int> v(n);
    for(int i=0;i<n;i++){
        cin >> v[i];
    }
    int rt=-1;
    int rn=2e9;
    vector<int> s;
    int ans=0;
    for(int i=n-1;i>=0;i--){
        if(v[i]<=t){
            rn=min(rn,v[i]-i);
            ans++;
        }
        else{
            rt=max(rt,i);
            while(s.size() && t-s.back()>=rn){
                s.pop_back();
            }
            if(s.empty()){
                s.push_back(i);
                rn=2e9;
                continue;
            }
            g[s.back()].ch.push_back(i);
            s.push_back(i);
            rn=2e9;
        }
    }
    if(rt==-1){
        cout << n << "\n";
        return 0;
    }
    dfs(rt,rt);
    dfs2(rt,rt,1);
    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:87:18: 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]
   87 |     for(int i=d;i<z.size();i++){
      |                 ~^~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20