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Submission #980379

# Submission time Handle Problem Language Result Execution time Memory
980379 2024-05-12T06:52:16 Z vjudge1 Longest Trip (IOI23_longesttrip) C++17
5 / 100
 18 ms 1112 KB 
#include "longesttrip.h"
#include <bits/stdc++.h>

#include <vector>
#define MP make_pair
#define f first
#define s second
#define mid ((l+r)>>1)
typedef long long ll;
using namespace std;

mt19937_64 rnd(chrono::steady_clock::now().time_since_epoch().count());

const int INF = (int)1e6;

vector <int> auxa,auxb;

bool conectados(int A, int B) {
    auxa.clear(); auxb.clear();
    auxa.push_back(A);
    auxb.push_back(B);
    return are_connected(auxa,auxb);
}

struct linea{
    deque <int> lin;
    linea(){}
    linea(int A) {
        lin.push_front(A);
    }
    void unir(linea &B, int NB, int NA) {
        if (NA == lin.front() && NB == B.lin.front()) {
            while (!B.lin.empty()) {
                lin.push_front(B.lin.front());
                B.lin.pop_front();
            }
            return;
        }
        if (NA == lin.front() && NB == B.lin.back()) {
            while (!B.lin.empty()) {
                lin.push_front(B.lin.back());
                B.lin.pop_back();
            }
            return;
        }
        if (NA == lin.back() && NB == B.lin.front()) {
            while (!B.lin.empty()) {
                lin.push_back(B.lin.front());
                B.lin.pop_front();
            }
            return;
        }
        if (NA == lin.back() && NB == B.lin.back()) {
            while (!B.lin.empty()) {
                lin.push_back(B.lin.back());
                B.lin.pop_back();
            }
            return;
        }
        return;
    }
};

vector <int> caso_base(int N) {
    auxa.clear();
    auxa.push_back(0);
    if (conectados(0, 1)) auxa.push_back(1);
    return auxa;
}

void dfs(int nodo, vector <bool> &vis, vector <vector<int>> &g, vector <int> &ans, int anc1, int anc2) {
    ans.push_back(nodo);
    if (ans.size() > 1) {
        anc1 = -1;
        anc2 = -1;
    }
    vis[nodo] = true;
    for (auto &it : g[nodo]) {
        if (vis[it] || it == anc1 || it == anc2) continue;
        dfs(it, vis, g, ans, anc1, anc2);
    }
    return;
}

int bin(int l, int r, vector <int> &ar, vector <int> &bus) {
    if (l == r) return ar[l];
    auxa.clear();
    for (int i = l; i <= mid; i++) auxa.push_back(ar[i]);
    if (are_connected(auxa, bus)) return bin(l, mid, ar, bus);
    else return bin(mid + 1, r, ar, bus);
}

std::vector<int> longest_trip(int N, int D) {
    if (N <= 2) return caso_base(N);
    vector <linea> V;
    vector <int> ans;
    for (int i = 0; i < N; i++)
        V.push_back(linea(i));

    shuffle(V.begin(), V.end(), rnd);
    while (V.size() >= 5) {
        linea A = V.back();
        V.pop_back();
        linea B = V.back();
        V.pop_back();
        linea C = V.back();
        V.pop_back();
        linea D = V.back();
        V.pop_back();
        linea E = V.back();
        V.pop_back();

        if (conectados(A.lin.front(), B.lin.front())) {
            A.unir(B, B.lin.front(), A.lin.front());
            V.push_back(A);
            V.push_back(C);
            V.push_back(D);
            V.push_back(E);
            shuffle(V.begin(), V.end(), rnd);
            continue;
        }

        if (conectados(C.lin.front(), D.lin.front())) {
            C.unir(D, D.lin.front(), C.lin.front());
            if (conectados(E.lin.front(), A.lin.front())) {
                E.unir(A, A.lin.front(), E.lin.front());
                V.push_back(B);
            }
            else {
                E.unir(B, B.lin.front(), E.lin.front());
                V.push_back(A);
            }
            V.push_back(E);
            V.push_back(C);
            shuffle(V.begin(), V.end(), rnd);
            continue;
        }

        if (conectados(A.lin.front(), C.lin.front()) && conectados(B.lin.front(), D.lin.front())) {
            A.unir(C, C.lin.front(), A.lin.front());
            B.unir(D, D.lin.front(), B.lin.front());
            V.push_back(A);
            V.push_back(B);
            shuffle(V.begin(), V.end(), rnd);
            continue;
        }
        else {
            A.unir(D, D.lin.front(), A.lin.front());
            B.unir(C, C.lin.front(), B.lin.front());
            V.push_back(A);
            V.push_back(B);
            shuffle(V.begin(), V.end(), rnd);
            continue;
        }
    }


    shuffle(V.begin(), V.end(), rnd);
    while (V.size() >= 3) {
        linea A = V.back();
        V.pop_back();
        linea B = V.back();
        V.pop_back();
        linea C = V.back();
        V.pop_back();
        if (conectados(A.lin.front(), B.lin.front())) {
            A.unir(B, B.lin.front(), A.lin.front());
            V.push_back(A);
            V.push_back(C);
        }
        else if (conectados(A.lin.front(), C.lin.front())) {
            A.unir(C, C.lin.front(), A.lin.front());
            V.push_back(A);
            V.push_back(B);
        }
        else {
            B.unir(C, C.lin.front(), B.lin.front());
            V.push_back(B);
            V.push_back(A);
        }
        shuffle(V.begin(), V.end(), rnd);
    }

    linea A = V[0], B = V[1];
    vector <int> VA, VB;
    while (!V[1].lin.empty()) {
        VB.push_back(V[1].lin.front());
        V[1].lin.pop_front();
    }
    while (!V[0].lin.empty()) {
        VA.push_back(V[0].lin.front());
        V[0].lin.pop_front();
    }

    if (!are_connected(VA,VB)) {
        if (VA.size() > VB.size()) return VA;
        return VB;
    }

    V[0] = A; V[1] = B;

    bool c1 = false, c2 = false, c3 = false, c4 = false;
    c1 = conectados(V[0].lin.front(), V[1].lin.front());
    if (!c1) c2 = conectados(V[0].lin.front(), V[1].lin.back());
    if (!c1 && !c2) c3 = conectados(V[0].lin.back(), V[1].lin.back());
    if (!c1 && !c2 && !c3) c4 = conectados(V[0].lin.back(), V[1].lin.front());
    if (c1 || c2 || c3 || c4) {
        if (c1) V[1].unir(V[0], V[0].lin.front(), V[1].lin.front());
        else if (c2) V[1].unir(V[0], V[0].lin.front(), V[1].lin.back());
        else if (c3) V[1].unir(V[0], V[0].lin.back(), V[1].lin.back());
        else if (c4) V[1].unir(V[0], V[0].lin.back(), V[1].lin.front());

        while (!V[1].lin.empty()) {
            ans.push_back(V[1].lin.front());
            V[1].lin.pop_front();
        }
        return ans;
    }

    int ancla = bin(0, VA.size() - 1, VA, VB);
    vector <int> vancla;
    vancla.push_back(ancla);
    int ancla2 = bin(0, VB.size() - 1, VB, vancla);

    vector <vector<int>> g(N + 2);
    vector <bool> vis(N + 2);
    for (int i = 0; i < N + 2; i++)
        vis[i] = false;

    for (int i = 0; i < VA.size() - 1; i++) {
        g[VA[i]].push_back(VA[i + 1]);
        g[VA[i + 1]].push_back(VA[i]);
    }
    for (int i = 0; i < VB.size() - 1; i++) {
        g[VB[i]].push_back(VB[i + 1]);
        g[VB[i + 1]].push_back(VB[i]);
    }
    g[VA[VA.size() - 1]].push_back(VA[0]);
    g[VA[0]].push_back(VA[VA.size() - 1]);

    g[VB[VB.size() - 1]].push_back(VB[0]);
    g[VB[0]].push_back(VB[VB.size() - 1]);

    g[ancla].push_back(ancla2);
    g[ancla2].push_back(ancla);

    if (VA.size() != 1) {
        for (auto &it : g[ancla]) {
            if (it != ancla2) {
                dfs(it, vis, g, ans, ancla, ancla2);
                break;
            }
        }
    }
    else {
        for (auto &it : g[ancla2]) {
            if (it != ancla) {
                dfs(it, vis, g, ans, ancla, ancla2);
                break;
            }
        }
    }
    return ans;
}

Compilation message

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:230:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  230 |     for (int i = 0; i < VA.size() - 1; i++) {
      |                     ~~^~~~~~~~~~~~~~~
longesttrip.cpp:234:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  234 |     for (int i = 0; i < VB.size() - 1; i++) {
      |                     ~~^~~~~~~~~~~~~~~

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Incorrect 3 ms 600 KB Incorrect
3 Halted 0 ms 0 KB -

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 344 KB Output is correct
2 Correct 8 ms 344 KB Output is correct
3 Correct 11 ms 1112 KB Output is correct
4 Correct 11 ms 860 KB Output is correct
5 Correct 18 ms 1112 KB Output is correct

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 344 KB Output is correct
2 Correct 6 ms 344 KB Output is correct
3 Correct 11 ms 856 KB Output is correct
4 Correct 11 ms 856 KB Output is correct
5 Correct 17 ms 864 KB Output is correct
6 Correct 16 ms 344 KB Output is correct
7 Incorrect 1 ms 344 KB Incorrect
8 Halted 0 ms 0 KB -

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 344 KB Output is correct
2 Correct 8 ms 344 KB Output is correct
3 Correct 7 ms 600 KB Output is correct
4 Correct 11 ms 856 KB Output is correct
5 Correct 18 ms 936 KB Output is correct
6 Correct 11 ms 344 KB Output is correct
7 Correct 11 ms 340 KB Output is correct
8 Correct 11 ms 344 KB Output is correct
9 Correct 13 ms 856 KB Output is correct
10 Correct 18 ms 1112 KB Output is correct
11 Correct 18 ms 932 KB Output is correct
12 Correct 16 ms 856 KB Output is correct
13 Correct 16 ms 1112 KB Output is correct
14 Correct 8 ms 344 KB Output is correct
15 Correct 12 ms 596 KB Output is correct
16 Incorrect 8 ms 344 KB Incorrect
17 Halted 0 ms 0 KB -

Subtask #4
0.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 344 KB Output is correct
2 Correct 7 ms 344 KB Output is correct
3 Correct 10 ms 1008 KB Output is correct
4 Correct 11 ms 856 KB Output is correct
5 Correct 16 ms 856 KB Output is correct
6 Correct 9 ms 756 KB Output is correct
7 Incorrect 1 ms 344 KB Incorrect
8 Halted 0 ms 0 KB -