Submission #1080912

#	Time	Username	Problem	Language	Result	Execution time	Memory
1080912		asdasdqwer	Longest Trip (IOI23_longesttrip)	C++17	40 / 100	933 ms	1444 KiB

longesttrip

#include "longesttrip.h"

#include <bits/stdc++.h>
using namespace std;

std::vector<int> longest_trip(int N, int D) {
    vector<vector<int>> g(N);
    if (D == 3) {
        vector<int> v;
        for (int i=0;i<N;i++) {
            v.push_back(i);
        }
        return v;
    }

    for (int i=0;i<N;i++) {
        for (int j=i+1;j<N;j++) {
            if (are_connected({i}, {j})) {
                g[i].push_back(j);
                g[j].push_back(i);
            }
        }
    }

    int tries = 17;
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    for (int i=0;i<N;i++) {
        shuffle(g[i].begin(), g[i].end(), rng);
    }

    vector<int> lng;
    for (int i=0;i<tries;i++) {
        vector<int> tmp;
        vector<bool> vis(N, false);
        function<void(int)> dfs=[&](int node) {
            vis[node] = true;
            tmp.push_back(node);
            if (uniform_int_distribution<int>(0, 7)(rng) == 0) shuffle(g[node].begin(), g[node].end(), rng);

            for (int x:g[node]) {
                if (!vis[x]) {
                    dfs(x);
                    break;
                }
            }
        };

        dfs(uniform_int_distribution<int>(0, N-1)(rng));

        if (lng.size() < tmp.size()) {
            lng = tmp;
        }

        if (lng.size() == N) return lng;
    }

    return lng;
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:54:24: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   54 |         if (lng.size() == N) return lng;
      |             ~~~~~~~~~~~^~~~

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