Submission #1238734

#	Time	Username	Problem	Language	Result	Execution time	Memory
1238734		matsakyannn	Longest Trip (IOI23_longesttrip)	C++20	15 / 100	5 ms	420 KiB

longesttrip

#include <bits/stdc++.h>
#include "longesttrip.h"
using namespace std;

#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x << ' '; print(x); cerr << endl;
#else
#define dbg(x)
#endif 

void print(int x) {cerr << x;}
void print(long long x) {cerr << x;}
void print(char x) {cerr << x;}
void print(string x) {cerr << x;}
void print(double x) {cerr << x;}
template <class T> void print(vector <T> x);
template <class T> void print(set <T> x);
template <class T> void print(multiset <T> x);
template <class T, class V> void print(pair <T, V> x);
template <class T, class V> void print(map <T, V> x);
template <class T> void print(vector <T> x) {cerr << "[ "; for(auto i : x) {print(i); cerr << ' ';} cerr << "]";}
template <class T> void print(set <T> x) {cerr << "[ "; for(auto i : x) {print(i); cerr << ' ';} cerr << "]";}
template <class T> void print(multiset <T> x) {cerr << "[ "; for(auto i : x) {print(i); cerr << ' ';} cerr << "]";}
template <class T, class V> void print(pair <T, V> x) {cerr << "{"; print(x.first); cerr << ' '; print(x.second); cerr << "}";}
template <class T, class V> void print(map <T, V> x) {cerr << "[ "; for(auto i : x) {print(i); cerr << ' ';} cerr << "]";}

#define ll long long
#define pb push_back
#define ppb pop_back
#define PII pair <int, int>
#define PLL pair <ll, ll>
#define all(v) (v).begin(), (v).end()
#define OK cerr << "OK\n";
#define MP make_pair

vector <int> operator+(vector <int> x, vector <int> y){
    for(int i : y) x.pb(i);
    return x;
}

vector <int> longest_trip(int N, int D){
    vector <int> a, b;
    a.pb(0);
    b.pb(1);
    for(int i = 2; i < N; i++){
        if(are_connected({a.back()}, {i})){
            a.pb(i);
            continue;
        }
        if(are_connected({b.back()}, {i})){
            b.pb(i);
            continue;
        }
        reverse(all(b));
        a = a + b;
        b.clear();
        b.pb(i);
    }
    int lenA = a.size(), lenB = b.size();
    set <int> to_check;
    for(int i : a) to_check.insert(i);
    for(int i : b) to_check.insert(i);
    assert(to_check.size() == lenA + lenB); 
    if(!are_connected(a, b)){
        if(lenA > lenB) return a;
        else return b;
    }

    if(are_connected({a.back()}, {b.back()})){
        reverse(all(b));
        a = a + b;
        return a;
    }
    if(are_connected({a.back()}, {b.front()})){
        a = a + b;
        return a;
    }
    if(are_connected({a.front()}, {b.back()})){
        b = b + a;
        return b;
    }
    if(are_connected({a.front()}, {b.front()})){
        reverse(all(a));
        a = a + b;
        return a;
    }

    vector <int> A, B;
    int bottom = 0, top = lenA, resA, resB;
    B = b;
    while(bottom <= top){
        int mid = (top + bottom) / 2;
        A.clear();
        for(int i = bottom; i <= mid; i++){
            A.pb(i);
        }
        if(are_connected(A, B)){
            resA = mid;
            top = mid - 1;
        }
        else{
            bottom = mid + 1;
        }
    }

    bottom = 0, top = lenB;
    while(bottom <= top){
        int mid = (top + bottom) / 2;
        B.clear();
        for(int i = bottom; i <= mid; i++){
            B.pb(i);
        }
        if(are_connected({resA}, B)){
            resB = mid;
            top = mid - 1;
        }
        else{
            bottom = mid + 1;
        }
    }

    A.clear(), B.clear();
    for(int i = resA - 1; i >= 0; i--) A.pb(a[i]);
    for(int i = lenA - 1; i >= resA; i--) A.pb(a[i]);
    for(int i = resB; i < lenB; i++) B.pb(b[i]);
    for(int i = 0; i < resB; i++) B.pb(b[i]);
    A = A + b;
    return A;
}

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