oj.uz

Submission #252578

# Submission time Handle Problem Language Result Execution time Memory
252578 2020-07-25T21:28:26 Z Kubin Parachute rings (IOI12_rings) C++17
55 / 100
 4000 ms 136264 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> greater2, greater3;

size_t w3 = SIZE_MAX;
bamboo_forest drop_w3;

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) greater2.insert(u);
    if(base.deg[v] > 2) greater2.insert(v);
    if(base.deg[u] > 3) greater3.insert(u);
    if(base.deg[v] > 3) greater3.insert(v);

    if(not greater3.empty() and w3 == SIZE_MAX)
    {
        w3 = *greater3.begin();
        drop_w3 = bamboo_forest(n);
        for(auto [uu, vv] : edges)
            if(uu != w3 and vv != w3)
                drop_w3.edge(uu, vv);
    }
    else if(w3 != SIZE_MAX and (size_t)u != w3 and (size_t)v != w3)
        drop_w3.edge(u, 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 if(greater3.size() > 1)
        return 0;
    else
    {
        if(w3 != SIZE_MAX)
            return drop_w3.status == Ok;

        size_t result = 0, w = *greater2.begin();
        for(size_t i : graph[w])
            result += naive_try(i);
        result += naive_try(w);
        return result;
    }
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 3 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 3 ms 768 KB Output is correct
9 Correct 4 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 545 ms 49340 KB Output is correct
2 Correct 1168 ms 95292 KB Output is correct
3 Correct 1858 ms 136264 KB Output is correct
4 Correct 1270 ms 94284 KB Output is correct
5 Correct 1282 ms 94404 KB Output is correct
6 Correct 1443 ms 92608 KB Output is correct
7 Correct 1769 ms 134428 KB Output is correct
8 Correct 1921 ms 110344 KB Output is correct
9 Correct 2304 ms 118104 KB Output is correct
10 Correct 885 ms 91860 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 3 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 3 ms 768 KB Output is correct
9 Correct 4 ms 1024 KB Output is correct
10 Correct 3 ms 1024 KB Output is correct
11 Correct 14 ms 1024 KB Output is correct
12 Correct 12 ms 1680 KB Output is correct
13 Correct 37 ms 1820 KB Output is correct
14 Correct 6 ms 1408 KB Output is correct
15 Correct 5 ms 2176 KB Output is correct
16 Correct 7 ms 1408 KB Output is correct
17 Correct 67 ms 2204 KB Output is correct
18 Correct 15 ms 2584 KB Output is correct
19 Correct 6 ms 1408 KB Output is correct
20 Correct 58 ms 1604 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 3 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 3 ms 768 KB Output is correct
9 Correct 4 ms 1024 KB Output is correct
10 Correct 3 ms 1024 KB Output is correct
11 Correct 14 ms 1024 KB Output is correct
12 Correct 12 ms 1680 KB Output is correct
13 Correct 37 ms 1820 KB Output is correct
14 Correct 6 ms 1408 KB Output is correct
15 Correct 5 ms 2176 KB Output is correct
16 Correct 7 ms 1408 KB Output is correct
17 Correct 67 ms 2204 KB Output is correct
18 Correct 15 ms 2584 KB Output is correct
19 Correct 6 ms 1408 KB Output is correct
20 Correct 58 ms 1604 KB Output is correct
21 Correct 23 ms 4216 KB Output is correct
22 Correct 38 ms 6384 KB Output is correct
23 Correct 51 ms 7916 KB Output is correct
24 Correct 70 ms 10600 KB Output is correct
25 Correct 34 ms 8236 KB Output is correct
26 Correct 610 ms 11224 KB Output is correct
27 Correct 62 ms 9580 KB Output is correct
28 Execution timed out 4033 ms 8952 KB Time limit exceeded
29 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 3 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 3 ms 768 KB Output is correct
9 Correct 4 ms 1024 KB Output is correct
10 Correct 3 ms 1024 KB Output is correct
11 Correct 545 ms 49340 KB Output is correct
12 Correct 1168 ms 95292 KB Output is correct
13 Correct 1858 ms 136264 KB Output is correct
14 Correct 1270 ms 94284 KB Output is correct
15 Correct 1282 ms 94404 KB Output is correct
16 Correct 1443 ms 92608 KB Output is correct
17 Correct 1769 ms 134428 KB Output is correct
18 Correct 1921 ms 110344 KB Output is correct
19 Correct 2304 ms 118104 KB Output is correct
20 Correct 885 ms 91860 KB Output is correct
21 Correct 14 ms 1024 KB Output is correct
22 Correct 12 ms 1680 KB Output is correct
23 Correct 37 ms 1820 KB Output is correct
24 Correct 6 ms 1408 KB Output is correct
25 Correct 5 ms 2176 KB Output is correct
26 Correct 7 ms 1408 KB Output is correct
27 Correct 67 ms 2204 KB Output is correct
28 Correct 15 ms 2584 KB Output is correct
29 Correct 6 ms 1408 KB Output is correct
30 Correct 58 ms 1604 KB Output is correct
31 Correct 23 ms 4216 KB Output is correct
32 Correct 38 ms 6384 KB Output is correct
33 Correct 51 ms 7916 KB Output is correct
34 Correct 70 ms 10600 KB Output is correct
35 Correct 34 ms 8236 KB Output is correct
36 Correct 610 ms 11224 KB Output is correct
37 Correct 62 ms 9580 KB Output is correct
38 Execution timed out 4033 ms 8952 KB Time limit exceeded
39 Halted 0 ms 0 KB -