Submission #1081727

#	Time	Username	Problem	Language	Result	Execution time	Memory
1081727		slivajan	Longest Trip (IOI23_longesttrip)	C++17	15 / 100	8 ms	600 KiB

longesttrip

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

using namespace std;

typedef int un;
typedef vector<un> vuc;
typedef deque<un> duc;

#define REP(i, a, b) for (un i = (un)a; i < (un)b; i++)
#define FEAC(i, a) for (auto&& i : a)
#define ALL(x) (x).begin(), (x).end()
#define vec vector
#define DEB(x) cerr << #x << " = " << x << endl;

un bs(un from, vuc field){
    un L = 0;
    un R = field.size();

    while (R-L > 1)
    {
        un M = (L+R)/2;

        if (are_connected({from}, vuc(field.begin() + L, field.begin()+M))){
            R = M;
        }
        else{
            L = M;
        }
    }

    return field[L];
    
}

std::vector<int> longest_trip(int N, int D)
{
    if (D == 3){
        vuc ret(N);
        iota(ALL(ret), 0);
        return ret;
    }

    if (D == 2){
        duc ret;
        
        if (not are_connected({0}, {1})){
            ret = {0, 2, 1};
        }
        else if (not are_connected({1}, {2})){
            ret = {1, 0, 2};
        }
        else {
            ret = {0, 1, 2};
        }

        REP(i, 3, N){
            if (are_connected({ret.back()}, {i})){
                ret.push_back(i);
            }
            else{
                ret.push_front(i);
            }
        }

        return vuc(ALL(ret));
    }

    if (D == 1){
        vuc ret = {0};
        vec<bool> was_used(N, false);
        was_used[0] = true;

        while (true)
        {
            vuc not_used = {};
            REP(i, 0, N){
                if (not was_used[i]){
                    not_used.push_back(i);
                }
            }

            if (not are_connected(not_used, {ret[ret.size()-1]})){
                if (ret.size() > not_used.size()){
                    return ret;
                }
                else{
                    return not_used;
                }
            }

            un now = bs(ret[ret.size()-1], not_used);
            ret.push_back(now);
            was_used[now] = true;
        }
        
        return ret;
    }
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:99:1: warning: control reaches end of non-void function [-Wreturn-type]
   99 | }
      | ^

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