Submission #848876

#	Time	Username	Problem	Language	Result	Execution time	Memory
848876		d4xn	Longest Trip (IOI23_longesttrip)	C++17	5 / 100	972 ms	948 KiB

longesttrip

#include "longesttrip.h"
#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()

const int N = 256, T = 1e3;

mt19937 rng(time(nullptr) + (uint64_t) new char);

int cnt;
vector<int> adj[N], ans, curr;
bitset<N> vis;

void dfs(int u) {
    vis[u] = 1;
    curr.push_back(u);

    cnt++;
    if (cnt > T) {
        if (curr.size() > ans.size()) ans = curr;
        return;
    }

    //shuffle(all(adj[u]), rng);
    for (int& v : adj[u]) {
        if (vis[v]) continue;
        dfs(v);
        if (cnt > T) return;
    }
    
    if (curr.size() > ans.size()) ans = curr;
    vis[u] = 0;
    curr.pop_back();
}

vector<int> longest_trip(int N, int D)
{
    if (D == 3) {
        ans.resize(N);
        for (int i = 0; i < N; i++) ans[i] = i;
        return ans;
    }
    else {
        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);
                }
            }
        }

        for (int i = 0; i < 10; i++) {
            cnt = 0;
            vis.reset();
            curr.clear();

            for (int j = 0; j < N; j++) {
              shuffle(all(adj[j]), rng);
            }

            dfs(rng() % N);
        }
        return ans;
    }
}

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