Submission #500697

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
500697	2021-12-31T19:31:12 Z	blue	Firefighting (NOI20_firefighting)	C++17	14 / 100	210 ms	286804 KB

Firefighting

#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;

using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using vi = vector<int>;

const ll INF = 1'000'000'000'000'000'000LL;


    vvll dist(1+3000, vll(1+3000, INF));

        vvll has_edge(1+3000, vll(1+3000, 0));


            vector< pair<int, ll> > edge[1+3000];

int main()
{
    int N, K;
    cin >> N >> K;

    // for(int i = 1; i <= N; i++) dist[i][i] = 0;


    // vvll edge(1+N, vll(1+N, 0));


    for(int e = 1; e <= N-1; e++)
    {
        int a, b, d;
        cin >> a >> b >> d;
        has_edge[a][b] = has_edge[b][a] = 1;
        // dist[a][b] = dist[b][a] = d;
        // edge[a][b] = edge[b][a] = 1;

        edge[a].push_back({b, d});
        edge[b].push_back({a, d});
    }

    for(int i = 1; i <= N; i++)
    {
        queue<int> tbv;
        tbv.push(i);
        dist[i][i] = 0;
        while(!tbv.empty())
        {
            int u = tbv.front();
            tbv.pop();

            for(auto q: edge[u])
            {
                int v = q.first;
                ll w = q.second;

                if(dist[i][v] < INF) continue;

                dist[i][v] = dist[i][u] + w;
                tbv.push(v);
            }
        }
    }

    // for(int k = 1; k <= N; k++)
    //     for(int i = 1; i <= N; i++)
    //         for(int j = 1; j <= N; j++)
    //             dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);

    vi par(1+N, -1);
    for(int i = 2; i <= N; i++)
    {
        for(int j = 1; j <= N; j++)
        {
            if(j == i) continue;
            if(dist[1][i] == dist[1][j] + dist[j][i] && has_edge[i][j] == 1)
            {
                par[i] = j;
                break;
            }
        }
    }

    if(N <= 100)
    {
        vector<pair<ll, int> > V;
        for(int i = 1; i <= N; i++) V.push_back({dist[1][i], i});

        sort(V.begin(), V.end());

        vi res;

        reverse(V.begin(), V.end());

        vi covered(1+N, 0);

            // if(N >= 100) while(1);

        for(auto q: V)
        {
            int u = q.second;

            if(covered[u]) continue;

            int v = u;
            while(v != 1 && dist[par[v]][u] <= K) v = par[v];

            res.push_back(v);

            for(int i = 1; i <= N; i++)
                if(dist[i][v] <= K)
                    covered[i] = 1;
        }

        cout << int(res.size()) << '\n';
        for(int r: res) cout << r << ' ';
        cout << '\n';
    }



}

Subtask #1
0 / 3.0

#	Verdict	Execution time	Memory	Grader output
1	Runtime error	163 ms	286764 KB	Execution killed with signal 11
2	Halted	0 ms	0 KB	-

Subtask #2
5.0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	66 ms	141492 KB	Output is correct
2	Correct	56 ms	141508 KB	Output is correct
3	Correct	55 ms	141508 KB	Output is correct
4	Correct	55 ms	141492 KB	Output is correct
5	Correct	55 ms	141504 KB	Output is correct
6	Correct	56 ms	141512 KB	Output is correct
7	Correct	56 ms	141500 KB	Output is correct
8	Correct	61 ms	141504 KB	Output is correct
9	Correct	64 ms	141440 KB	Output is correct
10	Correct	55 ms	141452 KB	Output is correct
11	Correct	55 ms	141504 KB	Output is correct
12	Correct	56 ms	141552 KB	Output is correct
13	Correct	73 ms	141544 KB	Output is correct
14	Correct	71 ms	141552 KB	Output is correct
15	Correct	61 ms	141456 KB	Output is correct

Subtask #3
9.0 / 9.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	56 ms	141544 KB	Output is correct
2	Correct	64 ms	141500 KB	Output is correct
3	Correct	64 ms	141468 KB	Output is correct
4	Correct	59 ms	141520 KB	Output is correct
5	Correct	56 ms	141544 KB	Output is correct
6	Correct	57 ms	141516 KB	Output is correct
7	Correct	55 ms	141472 KB	Output is correct
8	Correct	59 ms	141540 KB	Output is correct
9	Correct	62 ms	141472 KB	Output is correct
10	Correct	57 ms	141524 KB	Output is correct
11	Correct	57 ms	141448 KB	Output is correct
12	Correct	56 ms	141528 KB	Output is correct
13	Correct	57 ms	141488 KB	Output is correct
14	Correct	57 ms	141508 KB	Output is correct
15	Correct	59 ms	141508 KB	Output is correct
16	Correct	61 ms	141476 KB	Output is correct
17	Correct	59 ms	141448 KB	Output is correct
18	Correct	75 ms	141508 KB	Output is correct
19	Correct	72 ms	141480 KB	Output is correct
20	Correct	56 ms	141508 KB	Output is correct
21	Correct	55 ms	141440 KB	Output is correct
22	Correct	56 ms	141444 KB	Output is correct
23	Correct	60 ms	141492 KB	Output is correct
24	Correct	69 ms	141488 KB	Output is correct
25	Correct	74 ms	141480 KB	Output is correct
26	Correct	57 ms	141432 KB	Output is correct