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Submission #491625

# Submission time Handle Problem Language Result Execution time Memory
491625 2021-12-03T14:48:38 Z blue Logičari (COCI21_logicari) C++17
110 / 110
 93 ms 26588 KB 
#include <iostream>
#include <vector>
#include <queue>
using namespace std;

const long long max_n = 100'000;

long long n;

const long long INF = 1'000'000;

long long dp[1+max_n][4];
vector<long long> children[1+max_n];
vector<long long> edge[1+max_n];
vector<long long> degree(1+max_n, 0);

void compute(long long u)
{
    // cerr << "compute " << u << '\n';
    vector<long long> sm(4, 0);
    long long min13 = INF;
    long long min02 = INF;
    for(long long v: children[u])
    {
        for(long long k = 0; k < 4; k++)
        {
            sm[k] += dp[v][k];
        }
        min13 = min(min13, dp[v][1] - dp[v][3]);
        min02 = min(min02, dp[v][0] - dp[v][2]);
    }
    // cerr << sm[0] << ' ' << sm[1] << ' ' << sm[2] << ' ' << sm[3] << ' ' << min13 << ' ' << min02 << '\n';
    dp[u][0] = 1 + sm[3] + min13;
    dp[u][1] = 1 + sm[3];
    dp[u][2] = sm[2] + min02;
    dp[u][3] = sm[2];

    for(long long k = 0; k < 4; k++) if(dp[u][k] >= INF) dp[u][k] = INF;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n;

    for(long long e = 1; e <= n; e++)
    {
        long long a, b;
        cin >> a >> b;

        edge[a].push_back(b);
        edge[b].push_back(a);

        degree[a]++;
        degree[b]++;
    }

    queue<long long> tbv;
    for(long long i = 1; i <= n; i++)
    {
        if(degree[i] == 1) tbv.push(i);
    }

    vector<bool> visit(1+n, 0);

    while(!tbv.empty())
    {
        long long u = tbv.front();
            // cerr << "bfs " << u << '\n';
        tbv.pop();
        visit[u] = 1;

        for(long long v: edge[u])
        {
            if(degree[v] == 1) continue;

            children[v].push_back(u);
            degree[v]--;
            if(degree[v] == 1)
                tbv.push(v);
        }

        compute(u);
    }


    long long s = 1;
    while(visit[s]) s++;

    vector<long long> chain;

    // cerr << "s = " << s << '\n';

    // cerr << "check\n";

    while(1)
    {
        chain.push_back(s);
        visit[s] = 1;

        long long nv = -1;
        for(long long v: edge[s])
        {
            if(visit[v]) continue;
            nv = v;
            break;
        }

        compute(s);

        // cerr << s << ' ' << nv << '\n';

        if(nv == -1) break;
        s = nv;

    }

    // for(long long i = 1; i <= n; i++)
    // {
    //     cerr << i << ": ";
    //     for(long long j = 0; j < 4; j++) cerr << dp[i][j] << ' ';
    //     cerr << '\n';
    // }

    // for(long long c: chain) cerr << c << ' ';
    // cerr << '\n';

    long long q = (long long)chain.size();

    //current index, current state, state -1
    long long dp2[q][4][4];

    /*
    0 = satisfied blue
    1 = unsatisfied blue
    2 = satisfied red
    3 = unsatisfied red
    */
    for(long long x = 0; x < 4; x++)
        for(long long y = 0; y < 4; y++)
            dp2[0][x][y] = INF;

    dp2[0][0][3] = dp[chain[0]][0];
    dp2[0][0][1] = dp[chain[0]][1];

    dp2[0][1][3] = dp[chain[0]][1];

    dp2[0][2][2] = dp[chain[0]][2];
    dp2[0][2][0] = dp[chain[0]][3];

    dp2[0][3][2] = dp[chain[0]][3];

    for(long long i = 1; i < q; i++)
    {
        for(long long y = 0; y < 4; y++)
        {
            dp2[i][0][y] = min(dp[chain[i]][0] + dp2[i-1][3][y], dp[chain[i]][1] + dp2[i-1][1][y]);
            dp2[i][1][y] = dp[chain[i]][1] + dp2[i-1][3][y];
            dp2[i][2][y] = min(dp[chain[i]][2] + dp2[i-1][2][y], dp[chain[i]][3] + dp2[i-1][0][y]);
            dp2[i][3][y] = dp[chain[i]][3] + dp2[i-1][2][y];
        }
    }

    long long ans = INF;
    for(long long x = 0; x < 4; x++)
        ans = min(ans, dp2[q-1][x][x]);

    if(ans == INF) ans = -1;

    cout << ans << '\n';
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5708 KB Output is correct
2 Correct 3 ms 5708 KB Output is correct
3 Correct 3 ms 5708 KB Output is correct
4 Correct 3 ms 5708 KB Output is correct
5 Correct 93 ms 26556 KB Output is correct
6 Correct 82 ms 26588 KB Output is correct
7 Correct 73 ms 26556 KB Output is correct
8 Correct 79 ms 26584 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5708 KB Output is correct
2 Correct 3 ms 5708 KB Output is correct
3 Correct 4 ms 5708 KB Output is correct
4 Correct 3 ms 5708 KB Output is correct
5 Correct 3 ms 5708 KB Output is correct
6 Correct 3 ms 5708 KB Output is correct
7 Correct 3 ms 5796 KB Output is correct
8 Correct 3 ms 5708 KB Output is correct
9 Correct 3 ms 5708 KB Output is correct
10 Correct 3 ms 5708 KB Output is correct
11 Correct 3 ms 5708 KB Output is correct
12 Correct 3 ms 5708 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5708 KB Output is correct
2 Correct 3 ms 5708 KB Output is correct
3 Correct 4 ms 5708 KB Output is correct
4 Correct 3 ms 5708 KB Output is correct
5 Correct 3 ms 5708 KB Output is correct
6 Correct 3 ms 5708 KB Output is correct
7 Correct 3 ms 5796 KB Output is correct
8 Correct 3 ms 5708 KB Output is correct
9 Correct 3 ms 5708 KB Output is correct
10 Correct 3 ms 5708 KB Output is correct
11 Correct 3 ms 5708 KB Output is correct
12 Correct 3 ms 5708 KB Output is correct
13 Correct 3 ms 5836 KB Output is correct
14 Correct 3 ms 5836 KB Output is correct
15 Correct 3 ms 5836 KB Output is correct
16 Correct 3 ms 5836 KB Output is correct
17 Correct 4 ms 5820 KB Output is correct
18 Correct 4 ms 5820 KB Output is correct
19 Correct 3 ms 5824 KB Output is correct
20 Correct 4 ms 5836 KB Output is correct
21 Correct 3 ms 5836 KB Output is correct
22 Correct 4 ms 5836 KB Output is correct
23 Correct 3 ms 5836 KB Output is correct
24 Correct 3 ms 5836 KB Output is correct

Subtask #4
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5708 KB Output is correct
2 Correct 3 ms 5708 KB Output is correct
3 Correct 3 ms 5708 KB Output is correct
4 Correct 3 ms 5708 KB Output is correct
5 Correct 93 ms 26556 KB Output is correct
6 Correct 82 ms 26588 KB Output is correct
7 Correct 73 ms 26556 KB Output is correct
8 Correct 79 ms 26584 KB Output is correct
9 Correct 3 ms 5708 KB Output is correct
10 Correct 3 ms 5708 KB Output is correct
11 Correct 4 ms 5708 KB Output is correct
12 Correct 3 ms 5708 KB Output is correct
13 Correct 3 ms 5708 KB Output is correct
14 Correct 3 ms 5708 KB Output is correct
15 Correct 3 ms 5796 KB Output is correct
16 Correct 3 ms 5708 KB Output is correct
17 Correct 3 ms 5708 KB Output is correct
18 Correct 3 ms 5708 KB Output is correct
19 Correct 3 ms 5708 KB Output is correct
20 Correct 3 ms 5708 KB Output is correct
21 Correct 3 ms 5836 KB Output is correct
22 Correct 3 ms 5836 KB Output is correct
23 Correct 3 ms 5836 KB Output is correct
24 Correct 3 ms 5836 KB Output is correct
25 Correct 4 ms 5820 KB Output is correct
26 Correct 4 ms 5820 KB Output is correct
27 Correct 3 ms 5824 KB Output is correct
28 Correct 4 ms 5836 KB Output is correct
29 Correct 3 ms 5836 KB Output is correct
30 Correct 4 ms 5836 KB Output is correct
31 Correct 3 ms 5836 KB Output is correct
32 Correct 3 ms 5836 KB Output is correct
33 Correct 83 ms 14564 KB Output is correct
34 Correct 84 ms 14496 KB Output is correct
35 Correct 68 ms 14580 KB Output is correct
36 Correct 69 ms 14484 KB Output is correct
37 Correct 13 ms 8012 KB Output is correct
38 Correct 66 ms 14664 KB Output is correct
39 Correct 6 ms 6476 KB Output is correct
40 Correct 79 ms 14472 KB Output is correct
41 Correct 41 ms 15568 KB Output is correct
42 Correct 44 ms 15856 KB Output is correct
43 Correct 68 ms 16252 KB Output is correct
44 Correct 70 ms 15512 KB Output is correct