Submission #1288987

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288987		sisi	Aliens (IOI16_aliens)	C++20	0 / 100	1 ms	332 KiB

aliens

#include<bits/stdc++.h>
using namespace std;
const int MAXN=5e4+10;
const long long INF=1e18+10;
vector<vector<pair<long long,int>>> dp;
vector<pair<int,int>>it;
stack<pair<int,int>>st;
void Divide_and_Conquer(int ll,int rr,int k,int optl,int optr){
    //cout<<"In Solve: "<<ll<<" "<<rr<<" "<<k<<endl;
    if(ll>rr){
        return;
    }
    int mid=(ll+rr)/2;
    dp[mid][k]=make_pair(INF,0);
    for(int j=optl;j<=optr;j++){

        if(j==0){
            //cout<<"Case: 1"<<endl;
            //cout<<it[n].second<<" - "<<it[j].first<<" "<<(it[n].second-it[j].first+1)<<endl;
            dp[mid][k]=min(dp[mid][k],make_pair(1LL*(it[mid].second-it[j].first+1)*(it[mid].second-it[j].first+1),j));
            continue;
        }
        /*cout<<"Case: 2"<<endl;
        cout<<dp[j-1][k-1].first<<" + "<<it[n].second<<" - "<<it[j].first<<" "<<(it[n].second-it[j].first+1)
                    <<" "<<it[j-1].second<<" + "<<it[j].first<<" "<<(it[j-1].second-it[j].first+1)<<endl;*/
        dp[mid][k]=min(dp[mid][k],make_pair(dp[j-1][k-1].first+(it[mid].second-it[j].first+1)*(it[mid].second-it[j].first+1)
                        -max(0,(it[j-1].second-it[j].first+1))*max(0,(it[j-1].second-it[j].first+1)),j));
    }
    //cout<<"Answer: "<<dp[mid][k].first<<" "<<dp[mid][k].second<<endl;
    int opt=dp[mid][k].second;
    Divide_and_Conquer(ll,mid-1,k,optl,opt);
    Divide_and_Conquer(mid+1,rr,k,opt,optr);

}
bool cmp(pair<int,int> a,pair<int,int>b){
    return a.first<b.first || (a.first==b.first && a.second>b.second);
}
long long take_photos(int n,int m,int k,vector<int> r,vector<int> c){
    dp.resize(n, vector<pair<long long,int>>(k, {0,0}));
    for(int i=0;i<n;i++){
        it.push_back({min(c[i],r[i]),max(c[i],r[i])});
    }
    sort(it.begin(),it.end(),cmp);
    st.push(it[0]);
    for(int i=1;i<n;i++){
        if(st.size()>0 && !(st.top().first<=it[i].first && it[i].second<=st.top().second)){
            st.push(it[i]);
        }
    }
    it.clear();
    while(!st.empty()){
        it.push_back(st.top());
        st.pop();
    }
    reverse(it.begin(),it.end());
    /*for(int i=0;i<it.size();i++){
        cout<<it[i].first<<" "<<it[i].second<<endl;
    }*/
    for(int i=0;i<it.size();i++){
        dp[i][1]=make_pair((it[i].second-it[0].first+1)*(it[i].second-it[0].first+1),i);
    }
    for(int kk=2;kk<=k;kk++){
        Divide_and_Conquer(0,it.size()-1,kk,0,it.size()-1);
        //cout<<"After Solve"<<endl;
    }
    return dp[it.size()-1][k].first;
}/*
1 4
2 3
2 4
3 8
4 7
*/

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