oj.uz

Submission #252574

# Submission time Handle Problem Language Result Execution time Memory
252574 2020-07-25T21:25:14 Z Kubin Parachute rings (IOI12_rings) C++17
55 / 100
 4000 ms 136384 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)
        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(greater3.empty())
        //    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 1 ms 384 KB Output is correct
2 Correct 3 ms 896 KB Output is correct
3 Correct 6 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 526 ms 49252 KB Output is correct
2 Correct 3711 ms 113200 KB Output is correct
3 Correct 1855 ms 136384 KB Output is correct
4 Correct 1397 ms 94280 KB Output is correct
5 Correct 1428 ms 94272 KB Output is correct
6 Correct 1254 ms 92440 KB Output is correct
7 Correct 1613 ms 134412 KB Output is correct
8 Correct 1877 ms 110316 KB Output is correct
9 Correct 2088 ms 117780 KB Output is correct
10 Correct 834 ms 91716 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 896 KB Output is correct
3 Correct 6 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 12 ms 1588 KB Output is correct
13 Correct 38 ms 1832 KB Output is correct
14 Correct 125 ms 1752 KB Output is correct
15 Correct 167 ms 2744 KB Output is correct
16 Correct 6 ms 1408 KB Output is correct
17 Correct 62 ms 2564 KB Output is correct
18 Correct 24 ms 2584 KB Output is correct
19 Correct 6 ms 1408 KB Output is correct
20 Correct 42 ms 1596 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 896 KB Output is correct
3 Correct 6 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 12 ms 1588 KB Output is correct
13 Correct 38 ms 1832 KB Output is correct
14 Correct 125 ms 1752 KB Output is correct
15 Correct 167 ms 2744 KB Output is correct
16 Correct 6 ms 1408 KB Output is correct
17 Correct 62 ms 2564 KB Output is correct
18 Correct 24 ms 2584 KB Output is correct
19 Correct 6 ms 1408 KB Output is correct
20 Correct 42 ms 1596 KB Output is correct
21 Correct 23 ms 4216 KB Output is correct
22 Correct 42 ms 6384 KB Output is correct
23 Correct 47 ms 7916 KB Output is correct
24 Execution timed out 4083 ms 9348 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 896 KB Output is correct
3 Correct 6 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 526 ms 49252 KB Output is correct
12 Correct 3711 ms 113200 KB Output is correct
13 Correct 1855 ms 136384 KB Output is correct
14 Correct 1397 ms 94280 KB Output is correct
15 Correct 1428 ms 94272 KB Output is correct
16 Correct 1254 ms 92440 KB Output is correct
17 Correct 1613 ms 134412 KB Output is correct
18 Correct 1877 ms 110316 KB Output is correct
19 Correct 2088 ms 117780 KB Output is correct
20 Correct 834 ms 91716 KB Output is correct
21 Correct 13 ms 1024 KB Output is correct
22 Correct 12 ms 1588 KB Output is correct
23 Correct 38 ms 1832 KB Output is correct
24 Correct 125 ms 1752 KB Output is correct
25 Correct 167 ms 2744 KB Output is correct
26 Correct 6 ms 1408 KB Output is correct
27 Correct 62 ms 2564 KB Output is correct
28 Correct 24 ms 2584 KB Output is correct
29 Correct 6 ms 1408 KB Output is correct
30 Correct 42 ms 1596 KB Output is correct
31 Correct 23 ms 4216 KB Output is correct
32 Correct 42 ms 6384 KB Output is correct
33 Correct 47 ms 7916 KB Output is correct
34 Execution timed out 4083 ms 9348 KB Time limit exceeded
35 Halted 0 ms 0 KB -