Submission #74189

#	Time	Username	Problem	Language	Result	Execution time	Memory
74189		MKopchev	Shortcut (IOI16_shortcut)	C++14	38 / 100	2045 ms	1000 KiB

shortcut

#include<bits/stdc++.h>
using namespace std;
const int nmax=1e6+42;
long long x[nmax];
long long find_shortcut(int n, vector<int> l, vector<int> d, int c)
{
    long long ans=1e18;
    x[0]=0;
    for(int i=1;i<n;i++)
        x[i]=x[i-1]+l[i-1];
    for(int p=0;p<n;p++)
        for(int q=p+1;q<n;q++)
        {
        long long now=0;
        //1<->1 type
        long long best=-1e18;
        for(int j=0;j<p;j++)
        {
            now=max(now,d[j]+x[j]+best);
            best=max(best,d[j]-x[j]);
        }
                //cout<<now<<endl;
        //3<->3 type
        best=-1e18;
        for(int j=q+1;j<n;j++)
        {
            now=max(now,d[j]+x[j]+best);
            best=max(best,d[j]-x[j]);
        }
               //cout<<now<<endl;
        //1<->3 type
        best=-1e18;
        for(int i=0;i<p;i++)
            best=max(best,d[i]+x[p]-x[i]);
        for(int j=q+1;j<n;j++)
            now=max(now,d[j]+x[j]-x[q]+best+min(1LL*c,x[q]-x[p]));
        //1<->2 type
        best=-1e18;
        for(int i=0;i<p;i++)
            best=max(best,d[i]-x[i]+x[p]);
        for(int j=p;j<=q;j++)
            now=max(now,best+d[j]+min(x[j]-x[p],x[q]-x[j]+c));
                //cout<<best<<" "<<now<<endl;
        //2<->3 type
        best=-1e18;
        for(int i=p;i<=q;i++)
            best=max(best,d[i]+min(x[i]-x[p]+c,x[q]-x[i]));
        for(int j=q+1;j<n;j++)
            now=max(now,best+d[j]+x[j]-x[q]);
                //cout<<best<<" "<<now<<endl;
        //2<->2 type
        /*
        if(x[q]-x[p]+c<0)
        for(int i=p;i<=q;i++)
            for(int j=i+1;j<=q;j++)
            now=max(now,d[i]+d[j]+x[q]-x[j]+c+x[i]-x[p]);
        else
        for(int i=p;i<=q;i++)
            for(int j=i+1;j<=q;j++)
            now=max(now,d[i]+d[j]+x[j]-x[i]);
        */
        /*
        for(int i=p;i<=q;i++)
            for(int j=i+1;j<=q;j++)
            now=max(now,d[i]+d[j]+min(x[j]-x[i],x[q]-x[j]+c+x[i]-x[p]));
        */
        //first is min
        deque< pair<long long/*difference*/,int/*where*/> > active={};
        long long C1=x[q]-x[p]+c;
        for(int j=p;j<=q;j++)
        {
            while(active.size()&&2*(x[j]-x[active.front().second])>C1)active.pop_front();
            if(active.size())
            {
                now=max(now,d[j]+x[j]+active.front().first);
            }
            pair<long long/*difference*/,int/*where*/> add={d[j]-x[j],j};
            while(active.size()&&active[active.size()-1].first<=add.first)active.pop_back();
            active.push_back(add);
        }
        //second is min
        long long add=-1e18;
        int pos=p;
        for(int j=p;j<=q;j++)
        {
            while(2*(x[j]-x[pos])>C1)
            {
                add=max(add,d[pos]+x[pos]-x[p]);
                pos++;
            }
                now=max(now,d[j]+x[q]-x[j]+c+add);
        }

        ans=min(ans,now);
        }

    return ans;
}
/*
int main()
{
cout<<find_shortcut(9, {10, 10, 10, 10, 10, 10, 10, 10},{20, 0, 30, 0, 0, 40, 0, 40, 0}, 30)<<endl;
//cout<<find_shortcut(4, {2, 2, 2},{1, 10, 10, 1}, 1)<<endl;
//cout<<find_shortcut(3, {1, 1},{1, 1, 1}, 3)<<endl;
//cout<<find_shortcut(2,{100},{1,2},10)<<endl;
return 0;
}
*/

• Subtask 1: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 7 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3