Submission #1063985

#	Time	Username	Problem	Language	Result	Execution time	Memory
1063985		amirhoseinfar1385	Longest Trip (IOI23_longesttrip)	C++17	15 / 100	7 ms	596 KiB

longesttrip

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

std::vector<int> longest_trip(int N, int D)
{
    if(D==3){
        vector<int>ret;
        for(int i=0;i<N;i++){
           ret.push_back(i);
        }
        return ret;
    }else if(D==2){
        deque<int>dq;
        int now=0;
        if(are_connected({0},{1})){
            dq.push_back(0);
            dq.push_back(1);
            now=2;
        }else{
            dq.push_back(0);
            dq.push_back(2);
            dq.push_back(1);
            now=3;
        }
        for(;now<N;now++){
            if(are_connected({dq.front()},{now})){
                dq.push_front(now);
            }else{
                dq.push_back(now);
            }
        }
        vector<int>ret;
        for(auto x:dq){
            ret.push_back(x);
        }
        return ret;
    }
    int n=N;
    vector<int>all;
    for(int i=0;i<n;i++){
        all.push_back(i);
    }
    vector<vector<int>>ans(2);
    ans[0].push_back(all[0]);
    for(int i=1;i<n;i++){
        int cn0=are_connected({ans[0].back()},{all[i]});
        int cn1=0;
        if((int)ans[1].size()>0){
            if(are_connected({ans[1].back()},{all[i]})){
                cn1=1;
            }
        }
        if(cn1==1&&cn0==1){
            ans[0].push_back(all[i]);
            while((int)ans[1].size()>0){
                ans[0].push_back(ans[1].back());
                ans[1].pop_back();
            }
        }else if(cn0==1){
            ans[0].push_back(all[i]);
        }else{
            ans[1].push_back(all[i]);
        }
    }
    if((int)ans[0].size()<(int)ans[1].size()){
        swap(ans[0],ans[1]);
    }
    vector<int>ret;
    if((int)ans[1].size()==0){
        return ans[0];
    }
    if(!are_connected({ans[0][0]},{ans[0].back()})){
        if(are_connected({ans[0].back()},{ans[1].back()})){
            for(int i=(int)ans[1].size()-1;i>=0;i--){
                ans[0].push_back(ans[1][i]);
            }
        }else{
            for(int i=0;i<(int)ans[0].size();i++){
                ans[1].push_back(ans[0][i]);
            }
            swap(ans[0],ans[1]);
        }
        return ans[0];
    }else if(!are_connected({ans[1][0]},{ans[1].back()})){
        swap(ans[0],ans[1]);
        if(are_connected({ans[0].back()},{ans[1].back()})){
            for(int i=(int)ans[1].size()-1;i>=0;i--){
                ans[0].push_back(ans[1][i]);
            }
        }else{
            for(int i=0;i<(int)ans[0].size();i++){
                ans[1].push_back(ans[0][i]);
            }
            swap(ans[0],ans[1]);
        }
        return ans[0];
    }else{
        if(!are_connected(ans[0],ans[1])){
            return ans[0];
        }
        int low1=0,high1=(int)ans[0].size(),mid1;
        while(high1-low1>1){
            mid1=(high1+low1)>>1;
            vector<int>bal;
            for(int i=mid1;i<high1;i++){
                bal.push_back(ans[0][i]);
            }
            if(are_connected(bal,ans[1])){
                low1=mid1;
            }else{
                high1=mid1;
            }
        }
        int low2=0,high2=(int)ans[1].size(),mid2;
        while(high2-low2>1){
            mid2=(high2+low2)>>1;
            vector<int>paee;
            for(int i=mid2;i<high2;i++){
                paee.push_back(ans[1][i]);
            }
            if(are_connected({ans[0][low1]},paee)){
                low2=mid2;
            }else{
                high2=mid2;
            }
        }
        for(int i=low1-1;i>=0;i--){
            ret.push_back(ans[0][i]);
        }
        for(int i=(int)ans[0].size()-1;i>=low1;i--){
            ret.push_back(ans[0][i]);
        }
        for(int i=low2;i<(int)ans[1].size();i++){
            ret.push_back(ans[1][i]);
        }
        for(int i=0;i<low2;i++){
            ret.push_back(ans[1][i]);
        }
    }
    return ret;
}

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 25
• Subtask 4: 0 / 60