Submission #1161199

#	Time	Username	Problem	Language	Result	Execution time	Memory
1161199		steveonalex	Longest Trip (IOI23_longesttrip)	C++20	100 / 100	5 ms	440 KiB

longesttrip

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}

ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}

//mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rng(1);
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double wow = (double) ((ull) rng()) / ((ull)(0-1));
    return wow * (r - l) + l;
}

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }

template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }
#include "longesttrip.h"


int o_cnt = 0;
bool b_connected(vector<int> a, vector<int> b){
    o_cnt++;
    return are_connected(a, b);
}

vector<int> longest_trip(int n, int d){
    o_cnt = 0;
    vector<int> perm(n);
    for(int i = 0; i < n; ++i) perm[i] = i;

    shuffle(ALL(perm), rng);

    vector<int> S1, S2;
    S1.push_back(perm[0]);

    for(int it = 1; it < n; ++it){
        int i = perm[it];
        if (S2.size()){
            if (it + 1 < n){
                int j = perm[it + 1];
                it++;

                if (are_connected({i}, {j})){
                    if (are_connected({S1.back()}, {i})){
                        S1.push_back(i); S1.push_back(j);
                    }
                    else{
                        S2.push_back(i); S2.push_back(j);
                    }
                    if (are_connected({S1.back()}, {S2.back()})){
                        while(S2.size()){
                            S1.push_back(S2.back());
                            S2.pop_back();
                        }
                    }
                }
                else{
                    if (are_connected({S1.back()}, {i}) && are_connected({S2.back()}, {j})){
                        S1.push_back(i); S2.push_back(j);
                    }
                    else{
                        S2.push_back(i); S1.push_back(j);
                    }

                }
            }
            else{
                vector<int> A = {S1.back()}, B = {S2.back()}, C = {i};
                if (b_connected(A, C)) {
                    S1.push_back(i);
                    if (b_connected(B, C)) {
                        while(S2.size()){
                            S1.push_back(S2.back());
                            S2.pop_back();
                        }
                    }
                }
                else S2.push_back(i);
            }
        }
        else{
            if (b_connected({S1.back()}, {i})) S1.push_back(i);
            else S2.push_back(i);
        }
    }

    if (S1.size() < S2.size()) swap(S1, S2);
    if (S2.empty()) return S1;
    if (!b_connected(S1, S2)) return S1;

    if (!b_connected({S1[0]}, {S1.back()})){
        if (b_connected({S1.back()}, {S2[0]})){
            for(int i: S2) S1.push_back(i);
            return S1;
        }
        else{
            reverse(ALL(S1));
            for(int i: S2) S1.push_back(i);
            return S1;
        }
    }
    if (S2.size() > 1 && !b_connected({S2[0]}, {S2.back()})){
        swap(S1, S2);
        if (b_connected({S1.back()}, {S2[0]})){
            for(int i: S2) S1.push_back(i);
            return S1;
        }
        else{
            reverse(ALL(S1));
            for(int i: S2) S1.push_back(i);
            return S1;
        }
    }

    int l = 0, r = S1.size() - 1;
    while(l < r){
        int mid = (l + r) >> 1;
        vector<int> X;
        for(int i = 0; i <= mid; ++i) X.push_back(S1[i]);

        if (b_connected(X, S2)) r = mid;
        else l = mid + 1;
    }

    int x = l;
    l = 0, r = S2.size() - 1;
    while(l < r){
        int mid = (l + r) >> 1;
        vector<int> X;
        for(int i = 0; i <= mid; ++i) X.push_back(S2[i]);

        if (b_connected({S1[x]}, X)) r = mid;
        else l = mid + 1;
    }

    int y = l;

    vector<int> ans;
    for(int i = 0; i < (int) S1.size(); ++i) ans.push_back(S1[(i + x) % S1.size()]);
    reverse(ALL(ans));
    for(int i = 0; i < (int) S2.size(); ++i) ans.push_back(S2[(i + y) % S2.size()]);
    return ans;
}

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