oj.uz

Submission #848885

# Submission time Handle Problem Language Result Execution time Memory
848885 2023-09-13T16:24:50 Z d4xn Longest Trip (IOI23_longesttrip) C++17
5 / 100
 1000 ms 728 KB 
#include "longesttrip.h"
#include <bits/stdc++.h>

using namespace std;

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

const int N = 256, T = 5e3;

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

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

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);
                    con[i][j] = con[j][i] = 1;
                }
            }
        }

        for (int i = 0; i < 2; i++) {
            cnt = 0;
            vis.reset();
            curr.clear();

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

            dfs(rng() % N);
        }

        curr.clear();
        curr.resize(N);
        for (int i = 0; i < N; i++) {
          curr[i] = i;
        }
        
        for (int i = 0; i < T; i++) {
          shuffle(all(curr), rng);
          int r = 0;
          for (int j = 0; j+1 < N; j++) {
            if (con[curr[j]][curr[j+1]]) r++;
            else break;
          }

          if (r+1 > ans.size()) {
            ans.clear();
            ans.resize(r+1);
            for (int j = 0; j <= r; j++) {
              ans[j] = curr[j];
            }
          }
        }

        return ans;
    }
}

Compilation message

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:82:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |           if (r+1 > ans.size()) {
      |               ~~~~^~~~~~~~~~~~

Subtask #0
0.0 / 0.0

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

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 408 KB Output is correct
2 Correct 1 ms 344 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 344 KB Output is correct
5 Correct 1 ms 344 KB Output is correct

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1026 ms 600 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 995 ms 692 KB Output is correct
2 Incorrect 471 ms 488 KB Incorrect
3 Halted 0 ms 0 KB -

Subtask #4
0.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 993 ms 436 KB Output is correct
2 Incorrect 470 ms 728 KB Incorrect
3 Halted 0 ms 0 KB -