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Submission #980264

# Submission time Handle Problem Language Result Execution time Memory
980264 2024-05-12T02:08:47 Z vjudge1 Longest Trip (IOI23_longesttrip) C++17
15 / 100
 1000 ms 2097152 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(286);

const int INF = (int)1e6;

bool conectados(int A, int B) {
    vector<int> a,b;
    a.push_back(A);
    b.push_back(B);
    return are_connected(a,b);
}

struct linea{
    deque <int> lin;
    linea(){}
    linea(int A) {
        lin.push_front(A);
    }
    void unir(linea B) {
        while (!B.lin.empty()) {
            lin.push_front(B.lin.front());
            B.lin.pop_front();
        }
        return;
    }
    void unirrevez(linea B) {
        while (!B.lin.empty()) {
            lin.push_front(B.lin.back());
            B.lin.pop_back();
        }
        return;
    }
    void unirrevez2(linea B) {
        while (!B.lin.empty()) {
            lin.push_back(B.lin.back());
            B.lin.pop_back();
        }
        return;
    }
};

vector <int> base(int N) {
    vector <int> ans;
    ans.push_back(0);
    if (conectados(0, 1)) ans.push_back(1);
    return ans;
}

void dfs(int nodo, int p, vector <vector<int>> &g, vector <int> &ans) {
    ans.push_back(nodo);
    for (auto &it : g[nodo]) {
        if (it == p) continue;
        dfs(it, nodo, g, ans);
    }
    return;
}

int bin(int l, int r, vector <int> &ar, vector <int> &bus) {
    if (l == r) return ar[l];
    vector <int> aux;
    for (int i = l; i <= mid; i++) aux.push_back(ar[i]);
    if (are_connected(aux, 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 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() >= 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())) {
            if (A.lin.size() < B.lin.size()) swap(A,B);
            A.unir(B);
            V.push_back(A);
            V.push_back(C);
        }
        else if (conectados(A.lin.front(), C.lin.front())) {
            if (A.lin.size() < C.lin.size()) swap(A,C);
            A.unir(C);
            V.push_back(A);
            V.push_back(B);
        }
        else {
            if (B.lin.size() < C.lin.size()) swap(B,C);
            B.unir(C);
            V.push_back(B);
            V.push_back(A);
        }
    }
    bool c1,c2,c3,c4;
    c1 = conectados(V[0].lin.front(), V[1].lin.front());
    c2 = conectados(V[0].lin.front(), V[1].lin.back());
    c3 = conectados(V[0].lin.back(), V[1].lin.back());
    c4 = conectados(V[0].lin.back(), V[1].lin.front());
    if (c1 || c2 || c3 || c4) {
        if (c1) V[1].unir(V[0]);
        else if (c2) {
            V[0].unirrevez(V[1]);
            swap(V[1],V[0]);
        }
        else if (c3) V[1].unirrevez2(V[0]);
        else if (c4) V[1].unirrevez(V[0]);
        while (!V[1].lin.empty()) {
            ans.push_back(V[1].lin.front());
            V[1].lin.pop_front();
        }
        return ans;
    }

    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;
    }

    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);
    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[VA[0]].push_back(VA[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, -1, g, ans);
                break;
            }
        }
    }
    else {
        for (auto &it : g[ancla2]) {
            if (it != ancla) {
                dfs(it, -1, g, ans);
                break;
            }
        }
    }
    return ans;
    return ans;
}

Compilation message

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:150:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  150 |     for (int i = 0; i < VA.size() - 1; i++) {
      |                     ~~^~~~~~~~~~~~~~~
longesttrip.cpp:154:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  154 |     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 2 ms 600 KB Output is correct

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 344 KB Output is correct
2 Correct 10 ms 344 KB Output is correct
3 Correct 8 ms 344 KB Output is correct
4 Correct 6 ms 344 KB Output is correct
5 Correct 6 ms 936 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 344 KB Output is correct
2 Correct 7 ms 344 KB Output is correct
3 Correct 6 ms 340 KB Output is correct
4 Correct 6 ms 344 KB Output is correct
5 Correct 5 ms 856 KB Output is correct
6 Correct 11 ms 344 KB Output is correct
7 Correct 8 ms 344 KB Output is correct
8 Correct 5 ms 344 KB Output is correct
9 Correct 6 ms 600 KB Output is correct
10 Correct 6 ms 688 KB Output is correct
11 Correct 6 ms 684 KB Output is correct
12 Correct 6 ms 856 KB Output is correct
13 Correct 6 ms 856 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 9 ms 344 KB Output is correct
3 Correct 6 ms 344 KB Output is correct
4 Correct 6 ms 344 KB Output is correct
5 Correct 5 ms 856 KB Output is correct
6 Correct 11 ms 344 KB Output is correct
7 Correct 8 ms 344 KB Output is correct
8 Correct 7 ms 600 KB Output is correct
9 Correct 5 ms 552 KB Output is correct
10 Correct 6 ms 680 KB Output is correct
11 Correct 6 ms 1112 KB Output is correct
12 Correct 6 ms 680 KB Output is correct
13 Correct 6 ms 688 KB Output is correct
14 Correct 15 ms 344 KB Output is correct
15 Correct 12 ms 344 KB Output is correct
16 Execution timed out 1511 ms 2097152 KB Time limit exceeded
17 Halted 0 ms 0 KB -

Subtask #4
0.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 344 KB Output is correct
2 Correct 7 ms 344 KB Output is correct
3 Correct 7 ms 344 KB Output is correct
4 Correct 6 ms 344 KB Output is correct
5 Correct 6 ms 1364 KB Output is correct
6 Correct 13 ms 344 KB Output is correct
7 Correct 7 ms 344 KB Output is correct
8 Correct 6 ms 344 KB Output is correct
9 Correct 6 ms 548 KB Output is correct
10 Correct 7 ms 940 KB Output is correct
11 Correct 7 ms 688 KB Output is correct
12 Correct 6 ms 856 KB Output is correct
13 Correct 6 ms 932 KB Output is correct
14 Correct 12 ms 344 KB Output is correct
15 Correct 17 ms 344 KB Output is correct
16 Execution timed out 1202 ms 2097152 KB Time limit exceeded
17 Halted 0 ms 0 KB -