Submission #1193322

#	Time	Username	Problem	Language	Result	Execution time	Memory
1193322		simona1230	Aliens (IOI16_aliens)	C++20	25 / 100	2092 ms	756 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>
using namespace std;

struct line
{
    long long a,b,id;
    line(){}
    line(long long _a,long long _b,int _id)
    {
        a=_a;
        b=_b;
        id=_id;
    }
    long long data(long long x)
    {
        return a*x+b;
    }
};

deque<line> cht,cht2;

int num;
pair<int,int> p[200001];
bool cmp(pair<int,int> p1,pair<int,int> p2)
{
    if(p1.second==p2.second)return p1.first<p2.first;
    return p1.second<p2.second;
}

long long sq(long long x)
{
    return x*x;
}

double pt(line l1,line l2)
{
    return (double)(l2.b-l1.b)/(double)(l1.a-l2.a);
}

void insert_(line l)
{
    //cout<<l.a<<" - "<<l.b<<endl;
    //while(cht2.size()>=2&&pt(cht2[cht2.size()-1],l)<pt(cht2[cht2.size()-2],l))cht2.pop_back();
    cht2.push_back(l);
}

long long value(long long x,int id)
{
    long long ans=1e18;
    for(int i=0;i<cht.size();i++)
        if(cht[i].id<id)
        {
            //cout<<cht[i].data(x)<<" ";
            ans=min(ans,cht[i].data(x));
        }
        //cout<<endl;
    return ans;
}

long long dp[200001];

long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c)
{
    for(int i=0; i<n; i++)
        p[i]= {min(r[i],c[i]),max(r[i],c[i])};
    sort(p,p+n,cmp);
    for(int i=0; i<n; i++)
    {
        if(i!=0&&p[i].second==p[i-1].second)continue;
        while(num!=0&&p[num-1].first>=p[i].first)num--;
        p[num++]=p[i];
    }

    long long ans=1e18;

    /*for(int i=0;i<num;i++)
    {
        dp[i][1]=sq(p[i].second-p[0].first+1);
        if(i==num-1)ans=min(ans,dp[i][1]);
        for(int j=2;j<=k;j++)
        {
            dp[i][j]=1e18;
            for(int l=1;l<=i;l++)
            {
                //dp[i][j]=min(dp[i][j],dp[l-1][j-1]+sq(p[i].second-p[l].first+1)-sq(max(0,p[l-1].second-p[l].first+1)));
                dp[i][j]=min(dp[i][j],sq(p[i].second+1)+
                (p[l].first*(-2)*p[i].second-2*p[l].first+dp[l-1][j-1]-sq(max(0,p[l-1].second-p[l].first+1))+sq(p[l].first)));
            }
            if(i==num-1)ans=min(ans,dp[i][j]);
        }
    }*/

    for(int i=0;i<num;i++)
    {
        dp[i]=sq(p[i].second-p[0].first+1);
        long long b=-2*p[i+1].first+dp[i]-sq(max(0,p[i].second-p[i+1].first+1))+sq(p[i+1].first);
        insert_({-2*p[i+1].first,b,i});
    }
    ans=dp[num-1];
    cht=cht2;
    cht2.clear();

    for(int j=2;j<=k;j++)
    {
        for(int i=0;i<num;i++)
        {
            dp[i]=sq(p[i].second+1)+value(p[i].second,i);
            long long b=-2*p[i+1].first+dp[i]-sq(max(0,p[i].second-p[i+1].first+1))+sq(p[i+1].first);
            if(i!=num-1)insert_({-2*p[i+1].first,b,i});
            //cout<<dp[i]<<" ";
        }
        //cout<<endl;
        ans=min(ans,dp[num-1]);
        cht=cht2;
        cht2.clear();
    }

    return ans;
}
/*
long long value(long long x,int id)
{
    if(cht.size()==1)return cht[0].data(x);
    long long ans=1e18;
    int l=0,r=cht.size()-2;
    while(l<=r)
    {
        int m=(l+r)/2;
        if(cht[m].id>=id)
        {
            r=m-1;
        }
        else
        {
            if(cht[m].data(x)<cht[m+1].data(x))
            {
                ans=cht[m].data(x);
                r=m-1;
            }
            else
            {
                ans=cht[m+1].data(x);
                l=m+2;
            }
        }
    }
    return ans;
}
*/

Compilation message (stderr)

aliens.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~
aliens_c.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 9 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40