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Submission #1049205

# Submission time Handle Problem Language Result Execution time Memory
1049205 2024-08-08T14:53:41 Z Zicrus Longest Trip (IOI23_longesttrip) C++17
0 / 100
 1 ms 392 KB 
#include <bits/stdc++.h>
#include "longesttrip.h"
using namespace std;
 
typedef long long ll;
 
vector<vector<ll>> adj;
vector<bool> vst;
mt19937 mt;
ll sz;

vector<int> mxRand(ll start) {
    ll n = adj.size();
    ll cur = start;
    vector<int> res = {(int)start};
loop:
    vst[cur] = true;
    shuffle(adj[cur].begin(), adj[cur].end(), mt);
    for (auto &e : adj[cur]) {
        if (!vst[e]) {
            cur = e;
            res.push_back(e);
            goto loop;
        }
    }
    for (auto &e : res) vst[e] = false;
    return res;
}

void dfs(ll cur) {
    vst[cur] = true;
    sz++;
    for (auto &e : adj[cur]) {
        if (vst[e]) continue;
        dfs(e);
    }
}
 
vector<int> longest_trip(int n, int d) {
    mt = mt19937(time(0));
    adj = vector<vector<ll>>(n);
    vst = vector<bool>(n);
    for (int i = 0; i < n; i++) {
        for (int j = i+1; j < n; j++) {
            if (are_connected({i}, {j})) {
                adj[i].push_back(j);
                adj[j].push_back(i);
            }
        }
    }

    sz = 0;
    vst = vector<bool>(n);
    dfs(0);
    bool comp0 = sz > n/2;

    ll start = 0;
    for (int i = 0; i < n; i++) {
        if (comp0 != vst[i]) continue;
        start = i;
        break;
    }
    for (int i = 0; i < n; i++) {
        if (comp0 != vst[i]) continue;
        if (adj[i].size() == 1) start = i;
    }
 
    vector<int> res;
    for (int i = 0; i < 50; i++) {
        vector<int> nw = mxRand(start);
        if (nw.size() > res.size()) res = nw;
    }
    return res;
}

Compilation message

longesttrip.cpp: In function 'std::vector<int> mxRand(ll)':
longesttrip.cpp:13:8: warning: unused variable 'n' [-Wunused-variable]
   13 |     ll n = adj.size();
      |        ^

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 392 KB Incorrect
2 Halted 0 ms 0 KB -

Subtask #1
0.0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Incorrect
2 Halted 0 ms 0 KB -

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Incorrect
2 Halted 0 ms 0 KB -

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Incorrect
2 Halted 0 ms 0 KB -

Subtask #4
0.0 / 60.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 344 KB Incorrect
2 Halted 0 ms 0 KB -