Submission #1077019

#	Time	Username	Problem	Language	Result	Execution time	Memory
1077019		lucri	Tortoise (CEOI21_tortoise)	C++17	73 / 100	125 ms	744 KiB

tortoise

#include <bits/stdc++.h>
using namespace std;
long long cost,n,v[10020],l[10020],r[10020],jump[10020],nr;
priority_queue<pair<int,int>>q;
bool candy(int time,int poz)
{
    bool ok=false;
    for(int i=poz;v[i]!=-1;++i)
        if(v[i]||jump[i])
            ok=true;
    if(ok==false)
        return true;
    for(int i=poz;v[i]!=-1;++i)
        if(v[i]&&time+i-poz<=(i-1)*2)
            return true;
    return false;
}
bool ok()
{
    int time=0;
    if(candy(0,1)==false)
        return false;
    time=r[1]-1;
    for(int i=1;i<=n;++i)
    {
        if(v[i]==-1)
        {
            if(v[i-1]==-1)
                ++time;
            continue;
        }
        if(r[i]-i==i-l[i]||r[i]-i==(i-1)-l[i])
        {
            if(candy(time-(i-1-l[i])+1,l[i]+1)==false)
                return false;
            time+=r[i]-(i-1);
        }
        if(r[i]-i<=i-l[i])
        {
            for(int j=1;j<=jump[i];++j)
            {
                if(time+r[i]-i>2*(i-1))
                    return false;
                time+=2*(r[i]-i);
            }
        }
        else
        {
            ++time;
            for(int j=1;j<=jump[i];++j)
            {
                if(time>2*(i-1))
                    return false;
                time+=2*(i-l[i]);
            }
        }
    }
    if(candy(time-(n-l[n])+1,l[n]+1)==false)
        return false;
    return true;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin>>n;
    for(int i=1;i<=n;++i)
        cin>>v[i];
    v[10010]=-1;
    l[0]=-10010;
    r[n+1]=10010;
    for(int i=1;i<=n;++i)
    {
        l[i]=l[i-1];
        if(v[i]==-1)
            l[i]=i;
    }
    for(int i=n;i>=1;--i)
    {
        r[i]=r[i+1];
        if(v[i]==-1)
            r[i]=i;
    }
    for(int i=1;i<=n;++i)
        q.push({-min(r[i]-i,i-l[i]),i});
    while(!q.empty())
    {
        int ind=q.top().second;
        q.pop();
        if(v[ind]==-1)
            continue;
        while(v[ind])
        {
            --v[ind];
            ++jump[ind];
            if(ok()==false)
            {
                ++v[ind];
                --jump[ind];
                break;
            }
        }
    }
    for(int i=1;i<=10010;++i)
        if(v[i]!=-1)
            nr+=v[i];
        else
        {
            if(nr)
                --cost;
            nr=0;
        }
    for(int i=1;i<=n;++i)
        if(v[i]!=-1)
            cost+=v[i];
    cout<<cost;
    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 10 / 10
• Subtask 3: 30 / 30
• Subtask 4: 25 / 25
• Subtask 5: 0 / 27