Submission #839845

# Submission time Handle Problem Language Result Execution time Memory
839845 2023-08-30T18:41:07 Z jtnydv25 Longest Trip (IOI23_longesttrip) C++17
15 / 100
34 ms 464 KB
#include "longesttrip.h"

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

#define ll long long
#define all(c) ((c).begin()), ((c).end())
#define sz(x) ((int)(x).size())

#ifdef LOCAL
#include <print.h>
#else
#define trace(...)
#define endl "\n" // remove in interactive
#endif

vector<vector<int>>  remove(vector<vector<int>> P, int a, int b){
    vector<vector<int>> ret;
    for(int i = 0; i < sz(P); i++) if(i != a && i != b) ret.push_back(P[i]);
    return ret;
}

vector<int> longest_trip(int n, int d){
    vector<vector<int>> paths;
    
    vector<int> nodes(n), b(n - 1);
    iota(all(nodes), 0);
    random_shuffle(all(nodes));
    for(int i = 0; i < n - 1; i++){
        b[i] = are_connected({nodes[i]}, {nodes[i + 1]});
    }
    vector<int> vis(n);
    // for(int i = 0; i < n; i++) if(!vis[i]){
    //     int j = i;
    //     vector<int> path;
    //     while(j < n){
    //         path.push_back(nodes[j]);
    //         vis[j] = true;
    //         if(j == n - 1) break;
    //         if(j < n - 1 && b[j]){
    //             j++;
    //             continue;
    //         } else if(j < n - 2 && !b[j + 1]){
    //             j += 2;
    //             continue;
    //         }
    //         break;
    //     }
    //     paths.push_back(path);
    // }
    for(int i = 0; i < n; i++) paths.push_back({i});
    if(sz(paths) == 1) return paths[0];
    // return {};
    while(sz(paths) > 2){
        int k = sz(paths);
        int p = rand() % k, q = rand() % k, r = rand() % k;
        while(p == q || q == r || p == r){
            p = rand() % k, q = rand() % k, r = rand() % k;
        }
        int pp = p, qq = q;
        if(!are_connected({paths[p][0]}, {paths[q][0]})){
            if(rand() % 2) swap(p, q);
            if(are_connected({paths[q][0]}, {paths[r][0]})){
                pp = q; qq = r;
            } else{
                qq = r;
            }
        }
        vector<int> newpath = paths[pp];
        reverse(all(newpath));
        copy(all(paths[qq]), back_inserter(newpath));
        paths = remove(paths, pp, qq);
        paths.push_back(newpath);
    }

    for(int i = 0; i < 2; i++){
        for(int j = 0; j < 2; j++){
            if(are_connected({paths[0][0]}, {paths[1][0]})){
                vector<int> Q = paths[0];
                reverse(all(Q));
                copy(all(paths[1]), back_inserter(Q));
                return Q;
            }
            reverse(all(paths[1]));
        }
        reverse(all(paths[0]));
    }
    vector<int> P = paths[0], Q = paths[1];
    if(are_connected(paths[0], paths[1])){
        for(int i = 0; i < 2; i++){
            while(sz(paths[i]) > 1){
                int k = sz(paths[i]) / 2;
                vector<int> lft(paths[i].begin(), paths[i].begin() + k);
                vector<int> rgt(paths[i].begin() + k, paths[i].end());
                if(are_connected(lft, paths[i ^ 1])){
                    paths[i] = lft;
                } else paths[i] = rgt;
            }
        }
        vector<int> final_path;
        int posP = find(all(P), paths[0][0]) - P.begin();
        int posQ = find(all(P), paths[0][0]) - P.begin();
        posP = (posP + 1) % sz(P);
        rotate(P.begin(), P.begin() + posP, P.end());
        rotate(Q.begin(), Q.begin() + posQ, Q.end());
        copy(all(Q), back_inserter(P));
        return P;
    }

    return sz(paths[0]) > sz(paths[1]) ? paths[0] : paths[1];
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB Output is correct
2 Incorrect 7 ms 336 KB Incorrect
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 12 ms 208 KB Output is correct
2 Correct 14 ms 256 KB Output is correct
3 Correct 21 ms 336 KB Output is correct
4 Correct 20 ms 352 KB Output is correct
5 Correct 26 ms 384 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 15 ms 208 KB Output is correct
2 Correct 13 ms 208 KB Output is correct
3 Correct 18 ms 336 KB Output is correct
4 Correct 19 ms 440 KB Output is correct
5 Correct 28 ms 360 KB Output is correct
6 Correct 13 ms 208 KB Output is correct
7 Correct 17 ms 208 KB Output is correct
8 Correct 15 ms 336 KB Output is correct
9 Correct 25 ms 464 KB Output is correct
10 Correct 26 ms 368 KB Output is correct
11 Correct 26 ms 364 KB Output is correct
12 Correct 25 ms 336 KB Output is correct
13 Correct 26 ms 336 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 12 ms 208 KB Output is correct
2 Correct 16 ms 236 KB Output is correct
3 Correct 16 ms 332 KB Output is correct
4 Correct 25 ms 332 KB Output is correct
5 Correct 31 ms 376 KB Output is correct
6 Correct 15 ms 208 KB Output is correct
7 Correct 11 ms 296 KB Output is correct
8 Correct 20 ms 336 KB Output is correct
9 Correct 26 ms 348 KB Output is correct
10 Correct 32 ms 356 KB Output is correct
11 Correct 32 ms 364 KB Output is correct
12 Correct 34 ms 368 KB Output is correct
13 Correct 28 ms 380 KB Output is correct
14 Incorrect 2 ms 208 KB Incorrect
15 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 15 ms 208 KB Output is correct
2 Correct 13 ms 208 KB Output is correct
3 Correct 22 ms 336 KB Output is correct
4 Correct 20 ms 296 KB Output is correct
5 Partially correct 28 ms 368 KB Output is partially correct
6 Correct 20 ms 236 KB Output is correct
7 Correct 20 ms 208 KB Output is correct
8 Correct 15 ms 336 KB Output is correct
9 Correct 24 ms 352 KB Output is correct
10 Partially correct 29 ms 372 KB Output is partially correct
11 Partially correct 25 ms 464 KB Output is partially correct
12 Partially correct 30 ms 336 KB Output is partially correct
13 Partially correct 34 ms 368 KB Output is partially correct
14 Incorrect 2 ms 208 KB Incorrect
15 Halted 0 ms 0 KB -