oj.uz

Submission #252569

# Submission time Handle Problem Language Result Execution time Memory
252569 2020-07-25T21:18:29 Z Kubin Parachute rings (IOI12_rings) C++17
55 / 100
 4000 ms 143736 KB 
#include <bits/stdc++.h>

using namespace std;

struct disjoint_sets
{
    vector<size_t> repr, rank;

    disjoint_sets(size_t n) : repr(n), rank(n)
    {
        for(size_t i = 0; i < n; i++)
            repr[i] = i;
    }

    size_t find(size_t v)
    {
        return v == repr[v] ? v : repr[v] = find(repr[v]);
    }

    bool unite(size_t u, size_t v)
    {
        if((u = find(u)) == (v = find(v)))
            return false;
        if(rank[u] > rank[v])
            swap(u, v);
        rank[v] += (rank[u] == rank[v]);
        repr[u] = v;
        return true;
    }
};

enum BambooForestStatus
{
    Ok,
    Cycles,
    Bad
};

struct bamboo_forest
{
    BambooForestStatus status = Ok;
    disjoint_sets dsets;
    vector<size_t> deg;
    size_t cycles = 0;

    bamboo_forest(size_t n) : dsets(n), deg(n) {}
    bamboo_forest() : bamboo_forest(0) {}

    BambooForestStatus edge(size_t u, size_t v)
    {
        deg[u]++; deg[v]++;
        if(deg[u] > 2 or deg[v] > 2)
            status = Bad;
        if((status == Ok or status == Cycles) and dsets.find(u) == dsets.find(v) and deg[u] == 2 and deg[v] == 2)
            status = Cycles, cycles++;
        else if(not dsets.unite(u, v))
            status = Bad;
        return status;
    }
};

size_t n;
vector<pair<size_t, size_t>> edges;
vector<vector<size_t>> graph;
bamboo_forest base;
size_t first_cycle_size;
unordered_set<size_t> major;

void Init(int _n)
{
    n = _n;
    base = bamboo_forest(n);
    graph.resize(n);
}

void Link(int u, int v)
{
    edges.emplace_back(u, v);
    graph[u].push_back(v);
    graph[v].push_back(u);

    auto pre = base.status;
    base.edge(u, v);

    if(pre == Ok and base.status == Cycles and base.cycles == 1)
    {
        auto w = base.dsets.find(u);
        for(size_t i = 0; i < n; i++)
            if(base.dsets.find(i) == w)
                first_cycle_size++;
    }
    if(base.deg[u] > 2)
        major.insert(u);
    if(base.deg[v] > 2)
        major.insert(v);
}

bool naive_try(size_t i)
{
    bamboo_forest re(n);
    for(auto [u, v] : edges)
        if(u != i and v != i)
            re.edge(u, v);
    return re.status == Ok;
}

int CountCritical()
{
    if(base.status == Ok)
        return n;
    else if(base.status == Cycles and base.cycles == 1)
        return first_cycle_size;
    else if(base.status == Cycles and base.cycles > 1)
        return 0;
    else
    {
        size_t result = 0;
        for(size_t i : graph[*major.begin()])
            result += naive_try(i);
        result += naive_try(*major.begin());
        return result;
    }
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 3 ms 768 KB Output is correct
3 Correct 5 ms 1024 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 3 ms 896 KB Output is correct
7 Correct 1 ms 768 KB Output is correct
8 Correct 2 ms 768 KB Output is correct
9 Correct 3 ms 1024 KB Output is correct
10 Correct 3 ms 1024 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 498 ms 49268 KB Output is correct
2 Correct 3989 ms 94420 KB Output is correct
3 Correct 2627 ms 143736 KB Output is correct
4 Correct 1334 ms 107784 KB Output is correct
5 Correct 1340 ms 107876 KB Output is correct
6 Correct 1352 ms 105804 KB Output is correct
7 Correct 2101 ms 140808 KB Output is correct
8 Correct 1974 ms 122860 KB Output is correct
9 Correct 2199 ms 131344 KB Output is correct
10 Correct 981 ms 104316 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 3 ms 768 KB Output is correct
3 Correct 5 ms 1024 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 3 ms 896 KB Output is correct
7 Correct 1 ms 768 KB Output is correct
8 Correct 2 ms 768 KB Output is correct
9 Correct 3 ms 1024 KB Output is correct
10 Correct 3 ms 1024 KB Output is correct
11 Correct 13 ms 1024 KB Output is correct
12 Correct 14 ms 1716 KB Output is correct
13 Correct 43 ms 1996 KB Output is correct
14 Correct 110 ms 1576 KB Output is correct
15 Correct 172 ms 2976 KB Output is correct
16 Correct 7 ms 1408 KB Output is correct
17 Correct 60 ms 1772 KB Output is correct
18 Correct 92 ms 2756 KB Output is correct
19 Correct 6 ms 1536 KB Output is correct
20 Correct 42 ms 1716 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 3 ms 768 KB Output is correct
3 Correct 5 ms 1024 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 3 ms 896 KB Output is correct
7 Correct 1 ms 768 KB Output is correct
8 Correct 2 ms 768 KB Output is correct
9 Correct 3 ms 1024 KB Output is correct
10 Correct 3 ms 1024 KB Output is correct
11 Correct 13 ms 1024 KB Output is correct
12 Correct 14 ms 1716 KB Output is correct
13 Correct 43 ms 1996 KB Output is correct
14 Correct 110 ms 1576 KB Output is correct
15 Correct 172 ms 2976 KB Output is correct
16 Correct 7 ms 1408 KB Output is correct
17 Correct 60 ms 1772 KB Output is correct
18 Correct 92 ms 2756 KB Output is correct
19 Correct 6 ms 1536 KB Output is correct
20 Correct 42 ms 1716 KB Output is correct
21 Correct 26 ms 4600 KB Output is correct
22 Correct 45 ms 7024 KB Output is correct
23 Correct 63 ms 8684 KB Output is correct
24 Execution timed out 4081 ms 7344 KB Time limit exceeded
25 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 3 ms 768 KB Output is correct
3 Correct 5 ms 1024 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 3 ms 896 KB Output is correct
7 Correct 1 ms 768 KB Output is correct
8 Correct 2 ms 768 KB Output is correct
9 Correct 3 ms 1024 KB Output is correct
10 Correct 3 ms 1024 KB Output is correct
11 Correct 498 ms 49268 KB Output is correct
12 Correct 3989 ms 94420 KB Output is correct
13 Correct 2627 ms 143736 KB Output is correct
14 Correct 1334 ms 107784 KB Output is correct
15 Correct 1340 ms 107876 KB Output is correct
16 Correct 1352 ms 105804 KB Output is correct
17 Correct 2101 ms 140808 KB Output is correct
18 Correct 1974 ms 122860 KB Output is correct
19 Correct 2199 ms 131344 KB Output is correct
20 Correct 981 ms 104316 KB Output is correct
21 Correct 13 ms 1024 KB Output is correct
22 Correct 14 ms 1716 KB Output is correct
23 Correct 43 ms 1996 KB Output is correct
24 Correct 110 ms 1576 KB Output is correct
25 Correct 172 ms 2976 KB Output is correct
26 Correct 7 ms 1408 KB Output is correct
27 Correct 60 ms 1772 KB Output is correct
28 Correct 92 ms 2756 KB Output is correct
29 Correct 6 ms 1536 KB Output is correct
30 Correct 42 ms 1716 KB Output is correct
31 Correct 26 ms 4600 KB Output is correct
32 Correct 45 ms 7024 KB Output is correct
33 Correct 63 ms 8684 KB Output is correct
34 Execution timed out 4081 ms 7344 KB Time limit exceeded
35 Halted 0 ms 0 KB -