Submission #957457

#	Time	Username	Problem	Language	Result	Execution time	Memory
957457		Turkhuu	가장 긴 여행 (IOI23_longesttrip)	C++17	100 / 100	11 ms	952 KiB

longesttrip

#include "longesttrip.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> longest_trip(int N, int D) {
    if (D > 1) {
        deque<int> a;
        if (are_connected({0}, {1})) {
            a = {0, 1};
            if (are_connected({0}, {2})) {
                a.push_front(2);
            } else {
                a.push_back(2);
            }
        } else {
            a = {0, 2, 1};
        }
        for (int i = 3; i < N; i++) {
            if (are_connected({a.front()}, {i})) {
                a.push_front(i);
            } else {
                a.push_back(i);
            }
        }
        return vector(a.begin(), a.end());
    }
    set<pair<int, int>> s;
    vector<int> a{0}, b{1};
    for (int i = 2; i < N; i++) {
        if (s.count(minmax(a.back(), b.back()))) {
            if (are_connected({i}, {a.back()})) {
                a.push_back(i);
            } else {
                s.insert(minmax(i, a.back()));
                b.push_back(i);
            }
        } else if (are_connected({i}, {a.back()})) {
            a.push_back(i);
        } else if (are_connected({i}, {b.back()})) {
            s.insert(minmax(i, a.back()));
            b.push_back(i);
        } else {
            s.insert(minmax(i, a.back()));
            s.insert(minmax(i, b.back()));
            a.insert(a.end(), b.rbegin(), b.rend());
            b = {i};
        }
    }
    if (!are_connected(a, b)) {
        return a.size() > b.size() ? a : b;
    }
    for (int i = 0; i < 2; i++) {
        for (int j = 0; j < 2; j++) {
            if (are_connected({a.back()}, {b.front()})) {
                a.insert(a.end(), b.begin(), b.end());
                return a;
            }
            reverse(b.begin(), b.end());
        }
        reverse(a.begin(), a.end());
    }
    int i, lo, hi;
    lo = 0, hi = a.size() - 1;
    while (lo < hi) {
        int mi = (lo + hi) / 2;
        are_connected(vector(a.begin(), a.begin() + mi + 1), b) ? hi = mi : lo = mi + 1;
    }
    i = lo, lo = 0, hi = b.size() - 1;
    while (lo < hi) {
        int mi = (lo + hi) / 2;
        are_connected(vector(b.begin(), b.begin() + mi + 1), {a[i]}) ? hi = mi : lo = mi + 1;
    }
    vector<int> ans;
    ans.insert(ans.end(), a.begin() + i + 1, a.end());
    ans.insert(ans.end(), a.begin(), a.begin() + i + 1);
    ans.insert(ans.end(), b.begin() + lo, b.end());
    ans.insert(ans.end(), b.begin(), b.begin() + lo);
    return ans;
}

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