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Submission #980359

# Submission time Handle Problem Language Result Execution time Memory
980359 2024-05-12T06:14:16 Z vjudge1 Longest Trip (IOI23_longesttrip) C++17
15 / 100
 16 ms 1368 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));

    while (V.size() >= 4) {
        shuffle(V.begin(), V.end(), rnd);
        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();

        // 1: A - B
        // 2: B - C
        // 3: C - D
        // 4: D - A
        // 5: A - C
        // 6: B - D

        bool p1, p2, p3, p4, p5, p6;

        p1 = conectados(A.lin.front(), B.lin.front());

        if (p1) {
            A.unir(B, B.lin.front(), A.lin.front());
            V.push_back(A);
            V.push_back(C);
            V.push_back(D);
            continue;
        }

        p3 = conectados(C.lin.front(), D.lin.front());

        if (p3) {
            C.unir(D, D.lin.front(), C.lin.front());
            V.push_back(A);
            V.push_back(B);
            V.push_back(C);
            continue;
        }

        p5 = conectados(A.lin.front(), C.lin.front());

        //p5 y p6
        if (p5) {
            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);
            continue;
        }

        //p2 y p4
        B.unir(C, C.lin.front(), B.lin.front());
        A.unir(D, D.lin.front(), A.lin.front());
        V.push_back(A);
        V.push_back(B);
    }

    while (V.size() >= 3) {
        shuffle(V.begin(), V.end(), rnd);
        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);
        }
    }

    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:118:18: warning: unused variable 'p2' [-Wunused-variable]
  118 |         bool p1, p2, p3, p4, p5, p6;
      |                  ^~
longesttrip.cpp:118:26: warning: unused variable 'p4' [-Wunused-variable]
  118 |         bool p1, p2, p3, p4, p5, p6;
      |                          ^~
longesttrip.cpp:118:34: warning: unused variable 'p6' [-Wunused-variable]
  118 |         bool p1, p2, p3, p4, p5, p6;
      |                                  ^~
longesttrip.cpp:229:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  229 |     for (int i = 0; i < VA.size() - 1; i++) {
      |                     ~~^~~~~~~~~~~~~~~
longesttrip.cpp:233:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  233 |     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 Correct 4 ms 600 KB Output is correct

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 344 KB Output is correct
2 Correct 7 ms 344 KB Output is correct
3 Correct 7 ms 600 KB Output is correct
4 Correct 10 ms 608 KB Output is correct
5 Correct 16 ms 688 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 344 KB Output is correct
2 Correct 7 ms 344 KB Output is correct
3 Correct 7 ms 504 KB Output is correct
4 Correct 10 ms 344 KB Output is correct
5 Correct 13 ms 1104 KB Output is correct
6 Correct 9 ms 344 KB Output is correct
7 Correct 7 ms 344 KB Output is correct
8 Correct 8 ms 600 KB Output is correct
9 Correct 8 ms 764 KB Output is correct
10 Correct 13 ms 936 KB Output is correct
11 Correct 14 ms 856 KB Output is correct
12 Correct 14 ms 1192 KB Output is correct
13 Correct 14 ms 1112 KB Output is correct

Subtask #3
0.0 / 25.0

# 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 8 ms 600 KB Output is correct
4 Correct 14 ms 1112 KB Output is correct
5 Correct 15 ms 856 KB Output is correct
6 Correct 9 ms 344 KB Output is correct
7 Correct 7 ms 344 KB Output is correct
8 Correct 8 ms 1368 KB Output is correct
9 Correct 9 ms 552 KB Output is correct
10 Correct 14 ms 692 KB Output is correct
11 Correct 13 ms 1112 KB Output is correct
12 Correct 14 ms 856 KB Output is correct
13 Correct 14 ms 1104 KB Output is correct
14 Correct 8 ms 344 KB Output is correct
15 Incorrect 3 ms 344 KB Incorrect
16 Halted 0 ms 0 KB -

Subtask #4
0.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 344 KB Output is correct
2 Correct 8 ms 600 KB Output is correct
3 Correct 7 ms 500 KB Output is correct
4 Correct 10 ms 600 KB Output is correct
5 Correct 14 ms 1112 KB Output is correct
6 Correct 9 ms 344 KB Output is correct
7 Correct 7 ms 344 KB Output is correct
8 Correct 7 ms 344 KB Output is correct
9 Correct 9 ms 604 KB Output is correct
10 Correct 14 ms 944 KB Output is correct
11 Correct 15 ms 856 KB Output is correct
12 Correct 14 ms 936 KB Output is correct
13 Correct 14 ms 1112 KB Output is correct
14 Correct 7 ms 344 KB Output is correct
15 Incorrect 3 ms 344 KB Incorrect
16 Halted 0 ms 0 KB -