Submission #845919

#	Time	Username	Problem	Language	Result	Execution time	Memory
845919		belgianbot	Longest Trip (IOI23_longesttrip)	C++17	15 / 100	11 ms	696 KiB

longesttrip

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

using namespace std;

std::vector<int> longest_trip(int N, int D)
{
    list <int> l1(0),l2(0);
    l1.push_back(0);
    for (int i(1); i < N; i++) {

        if (are_connected({i},{l1.back()})) {

            l1.push_back(i);
        }
        else if (l2.empty()) l2.push_back(i);
        else if (are_connected({i},{l2.front()})) {

            l2.push_front(i);
        }
        else {
            l1.insert(l1.end(), l2.begin(), l2.end());
            l2.clear();
            l2.push_back(i);
        }
    }
    vector< int > v1, v2;

    while (!l1.empty()) {
        v1.push_back(l1.front());
        l1.pop_front();
    }
    while (!l2.empty()) {
        v2.push_back(l2.front());
        l2.pop_front();
    }
    if (v2.empty()) return v1;
    if (!are_connected(v1, v2)) {
        if (v1.size() > v2.size()) return v1;
        return v2;
    }
    if (int (v1.size()) != 1 && !are_connected({v1[0]}, {v1.back()})) {
        if (are_connected({v2[0]}, {v1.back()})) {
            v1.insert(v1.end(), v2.begin(), v2.end());
        }

        else {
            v1.insert(v1.begin(), v2.rbegin(), v2.rend());
        }
        return v1;
    }

    if ( int(v2.size()) != 1 && !are_connected({v2[0]}, {v2.back()})) {
        if (are_connected({v1.back()}, {v2[0]})) {
            v1.insert(v1.end(), v2.begin(), v2.end());
        }

        else {
            v1.insert(v1.end(), v2.rbegin(), v2.rend());
        }
        return v1;
    }
    int l=0, r=v1.size();
    while (l<r) {
        int mid=(l+r)/2;
        if (are_connected(vector<int>(v1.begin(), v1.begin()+ mid + 1), v2)) r=mid;
        else l=mid+1;
    }

    int empl1=l;
    l=0; r=v2.size();
    while (l<r) {
        int mid=(l+r)/2;
        if (are_connected(vector<int>(v2.begin(), v2.begin()+ mid + 1), v1)) r=mid;
        else l=mid+1;
    }
    
    int empl2=l;
    vector<int> ans = vector<int> (v1.begin() + empl1 + 1, v1.end());
    ans.insert(ans.end(), v1.begin(), v1 . begin() + empl1 + 1);
    ans.insert(ans.end(), v2.begin() + empl2, v2.end());
    ans.insert(ans.end(),v2.begin(), v2.begin() + empl2);
    return ans;
}

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