제출 #1239975

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1239975		ZeroCool	가장 긴 여행 (IOI23_longesttrip)	C++20	15 / 100	6 ms	420 KiB

longesttrip

#include "longesttrip.h"
#include <bits/stdc++.h>

using namespace std;

#define ar array
#define all(v) v.begin(), v.end()

std::vector<int> longest_trip(int n, int d){
    vector<int> P;
    vector<int> Q;
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    vector<int> ord(n);
    iota(all(ord), 0);
    shuffle(all(ord), rng);
    bool kur = 0;
    for(auto i: ord){
        vector<ar<int,2> > v;
        if(P.empty()){
            P.push_back(i);
            continue;
        }
        if(Q.empty()){
            Q.push_back(i);
            continue;
        }
        if(are_connected({P.back()}, {i})){
            kur = 0;
            P.push_back(i);
        }else if(kur || are_connected({Q.back()}, {i})){
            kur = 1;
            Q.push_back(i);
        }else{
            kur = 0;
            while(P.size())Q.push_back(P.back()), P.pop_back();
            P.push_back(i);
        }
    }
    //assert(0);
    if(P.empty() || Q.empty() || !are_connected(P, Q))return (P.size() > Q.size() ? P : Q);
//    assert(0);
    
    for(int i = 0;i < 2;i++){
        for(int j = 0;j < 2;j++){
            if(are_connected({P.back()}, {Q.front()})){
                for(auto u: Q)P.push_back(u);
                return P;
            }
            reverse(all(Q));
        }
        reverse(all(P));
    }

    int l = -1, r = P.size();
    int L = -1, R = Q.size();

    while(r - l > 1 || R - L > 1){
        if(r - l > 1){
            int mid = (l + r) / 2;
            vector<int> a, b;
            for(int i = 0;i <= mid;i++)a.push_back(P[i]);
            for(int i = 0;i < R;i++)b.push_back(Q[i]);
            if(are_connected(a, b))r = mid;
            else l = mid;
        }
        if(R - L > 1){
            int mid = (L + R) / 2;
            vector<int> a, b;
            for(int i = 0;i <= mid;i++)a.push_back(Q[i]);
            for(int i = 0;i < r;i++)b.push_back(Q[i]);
            if(are_connected(a, b))R = mid;
            else L = mid;
        }
    }

    //assert(are_connected({P[r]}, {Q[R]}));
    vector<int> ans;
    for(int i = r + 1;i < P.size();i++)ans.push_back(P[i]);
    for(int i = 0;i <= r;i++)ans.push_back(P[i]);
    for(int i = R;i < Q.size();i++)ans.push_back(Q[i]);
    for(int i = 0;i < R;i++)ans.push_back(Q[i]);
    return ans;
}

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