Submission #859085

#	Time	Username	Problem	Language	Result	Execution time	Memory
859085		Ludissey	Longest Trip (IOI23_longesttrip)	C++17	15 / 100	9 ms	600 KiB

longesttrip

#include <bits/stdc++.h>
#include "longesttrip.h"
using namespace std;
 
std::vector<int> longest_trip(int n, int d)
{
    vector<int> A;
    vector<int> B;
    A.push_back(0);
    for (int i = 1; i < n; i++)
    {
        if(are_connected({i}, {A.back()})) A.push_back(i);
        else if(B.size()==0 || are_connected({i}, {B.back()})) B.push_back(i);
        else {
            for (int x = B.size()-1; x >= 0; x--) A.push_back(B[x]);
            B.clear();
            B.push_back(i);
        }
    }
    if(A.size()<B.size()) swap(A,B);
    vector<int> outp;
    if(B.size()==0 || !are_connected({A},{B})) return A;
    int aN=A.size(), bN=B.size();
    if(are_connected({A[aN-1]}, {B[bN-1]})){
        for (int i = 0; i < aN; i++) outp.push_back(A[i]);
        for (int i = bN-1; i >= 0; i--) outp.push_back(B[i]);
        // cout << "method1\n";
    }else if(are_connected({A[aN-1]}, {B[0]})){
        for (int i = 0; i < aN; i++) outp.push_back(A[i]);
        for (int i = 0; i < bN; i++) outp.push_back(B[i]);
        //cout << A.size() << " " << B.size() << " method2\n";
    }else if(are_connected({A[0]}, {B[bN-1]})){
        for (int i = aN-1; i >= 0; i--) outp.push_back(A[i]);
        for (int i = bN-1; i >= 0; i--) outp.push_back(B[i]);
        //cout << "method3\n";
    }else if(are_connected({A[0]}, {B[0]})){
        for (int i = aN-1; i >= 0; i--) outp.push_back(A[i]);
        for (int i = 0; i < bN; i++) outp.push_back(B[i]);
        //cout << "method4\n";
    }else{
        int aConnect=0;
        int l=0, r=aN-1;
        while(l<r)
        {
            int mid=(l+r)/2;
            vector<int> vec;
            for (int i = l; i <= mid; i++) vec.push_back(A[i]);
            
            if(are_connected(vec, B)){
                aConnect=mid;
                r=mid-1;
            }else{
                l=mid+1;
            }
        }
        int bConnect=0;
        l=0, r=bN-1;
        while(l<r)
        {
            int mid=(l+r)/2;
            vector<int> vec;
            for (int i = l; i <= mid; i++) vec.push_back(B[i]);
            
            if(are_connected(vec, {A[aConnect]})){
                bConnect=mid;
                r=mid-1;
            }else{
                l=mid+1;
            }
        }
        for (int r = aConnect+1; r < aN; r++) outp.push_back(A[r]);
        for (int r = 0; r <= aConnect; r++) outp.push_back(A[r]);
        for (int r = bConnect; r < bN; r++) outp.push_back(B[r]);
        for (int r = 0; r < bConnect; r++) outp.push_back(B[r]);
        //cout << "methodLast\n";
    }
    return outp;
}

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