oj.uz

Submission #557567

# Submission time Handle Problem Language Result Execution time Memory
557567 2022-05-05T13:13:47 Z timreizin Parachute rings (IOI12_rings) C++17
37 / 100
 2448 ms 121284 KB 
#include <vector>
#include <numeric>
#include <array>
#include <algorithm>

using namespace std;

struct DSU
{
    int n, comps;
    vector<int> parent, size;
    vector<int> adj;
    array<int, 5> counter;
    int res, v;

    DSU(int n = 0, int v = -1) : n(n), v(v)
    {
        parent.resize(n);
        size.resize(n, 1);
        iota(parent.begin(), parent.end(), 0);
        comps = n;
        adj.resize(n);
        counter.fill(0);
        counter[0] = n;
        res = (v == -1 ? n : 1);
    }

    int getParent(int i)
    {
        if (parent[i] == i) return i;
        return parent[i] = getParent(parent[i]);
    }

    void unite(int a, int b)
    {
        if (res == 0) return;
        if (a == v || b == v) return;
        int wasCyc = comps - counter[0] - counter[1] / 2;
        --counter[min(adj[a], 4)];
        --counter[min(adj[b], 4)];
        ++adj[a];
        ++adj[b];
        ++counter[min(adj[a], 4)];
        ++counter[min(adj[b], 4)];
        if (counter[3] + counter[4] > 0)
        {
            res = 0;
            return;
        }
        a = getParent(a);
        b = getParent(b);
        if (a != b) --comps;
        int newCyc = comps - counter[0] - counter[1] / 2;
        if (v != -1 && newCyc > 0)
        {
            res = 0;
            return;
        }
        else if (v == -1)
        {
            if (newCyc >= 2)
            {
                res = 0;
                return;
            }
            if (newCyc == 1 && wasCyc == 0)
            {
                vector<int> cnt(n);
                for (int i = 0; i < n; ++i)
                {
                    if (adj[i] < 2) cnt[getParent(i)] = -1e9;
                    else ++cnt[getParent(i)];
                }
                res = 0;
                for (int i = 0; i < n; ++i) res = max(res, cnt[i]);
            }
        }
        if (a != b)
        {
            if (size[a] < size[b]) swap(a, b);
            size[a] += size[b];
            parent[b] = a;
        }
    }

};

int n;
vector<vector<int>> adj;
array<DSU, 8> dsu;
array<int, 5> counter;
vector<int> curs, dop;
vector<pair<int, int>> edges;

void Init(int N_)
{
    n = N_;
    adj.resize(n);
    dsu[0] = DSU(n);
    counter[0] = n;
    curs.push_back(-1);
}

void Link(int a, int b)
{
    int was3 = counter[3], was4 = counter[4];
    --counter[min((int)adj[a].size(), 4)];
    --counter[min((int)adj[b].size(), 4)];
    adj[a].push_back(b);
    adj[b].push_back(a);
    ++counter[min((int)adj[a].size(), 4)];
    ++counter[min((int)adj[b].size(), 4)];
    if (counter[4] > 1) return;
    if (counter[4] > was4)
    {
        curs.clear();
        dop.clear();
        for (int i = 0; i < 8; ++i) dsu[i].res = 0;
        if (adj[a].size() == 4) curs.push_back(a);
        if (adj[b].size() == 4) curs.push_back(b);
        dsu[0] = DSU(n, curs[0]);
        for (auto [a, b] : edges) dsu[0].unite(a, b);
    }
    else if (counter[3] > was3)
    {
        if (counter[3] > 4 && was3 <= 4)
        {
            curs.clear();
            dop.clear();
            for (int i = 0; i < 8; ++i) dsu[i].res = 0;
        }
        if (counter[3] <= 4)
        {
            if (was3 == 0) curs.clear();
            if (adj[a].size() == 3) curs.push_back(a);
            if (adj[b].size() == 3) curs.push_back(b);
            for (int i = 0; i < 8; ++i) dsu[i].res = 0;
            dop.clear();
            for (int i = 0; i < curs.size(); ++i)
            {
                dsu[i] = DSU(n, curs[i]);
                for (auto [a, b]: edges) dsu[i].unite(a, b);
            }
            if (curs.size() < 3)
            {
                for (int i = 0; i < n; ++i)
                {
                    if (adj[i].size() < 3)
                    {
                        bool was0 = false, was1 = curs.size() == 1;
                        for (int j : adj[i])
                        {
                            was0 = was0 || (j == curs[0]);
                            if (curs.size() == 2) was1 = was1 || (j == curs[1]);
                        }
                        if (was0 && was1)
                        {
                            dop.push_back(i);
                        }
                    }
                }
            }
            for (int i = 0; i < dop.size(); ++i)
            {
                dsu[i + curs.size()] = DSU(n, dop[i]);
                for (auto [a, b]: edges) dsu[i + curs.size()].unite(a, b);
            }
        }
    }
    for (int i = 0; i < curs.size(); ++i) dsu[i].unite(a, b);
    for (int i = 0; i < dop.size(); ++i) dsu[i + curs.size()].unite(a, b);
    edges.emplace_back(a, b);
}

int CountCritical()
{
    if (counter[4] > 1) return 0;
    int res = 0;
    for (int i = 0; i < 8; ++i) res += dsu[i].res;
    return res;
}

Compilation message

rings.cpp: In function 'void Link(int, int)':
rings.cpp:139:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  139 |             for (int i = 0; i < curs.size(); ++i)
      |                             ~~^~~~~~~~~~~~~
rings.cpp:163:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  163 |             for (int i = 0; i < dop.size(); ++i)
      |                             ~~^~~~~~~~~~~~
rings.cpp:170:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  170 |     for (int i = 0; i < curs.size(); ++i) dsu[i].unite(a, b);
      |                     ~~^~~~~~~~~~~~~
rings.cpp:171:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  171 |     for (int i = 0; i < dop.size(); ++i) dsu[i + curs.size()].unite(a, b);
      |                     ~~^~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 3 ms 724 KB Output is correct
3 Correct 3 ms 852 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 2 ms 468 KB Output is correct
6 Correct 2 ms 724 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 2 ms 528 KB Output is correct
9 Correct 4 ms 852 KB Output is correct
10 Correct 4 ms 852 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 451 ms 38936 KB Output is correct
2 Correct 1143 ms 88088 KB Output is correct
3 Correct 712 ms 98240 KB Output is correct
4 Correct 1117 ms 78476 KB Output is correct
5 Correct 1072 ms 78488 KB Output is correct
6 Correct 1048 ms 77196 KB Output is correct
7 Correct 695 ms 97732 KB Output is correct
8 Correct 2000 ms 112060 KB Output is correct
9 Correct 2448 ms 121284 KB Output is correct
10 Correct 807 ms 76288 KB Output is correct

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 3 ms 724 KB Output is correct
3 Correct 3 ms 852 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 2 ms 468 KB Output is correct
6 Correct 2 ms 724 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 2 ms 528 KB Output is correct
9 Correct 4 ms 852 KB Output is correct
10 Correct 4 ms 852 KB Output is correct
11 Correct 4 ms 852 KB Output is correct
12 Correct 9 ms 1476 KB Output is correct
13 Correct 10 ms 1576 KB Output is correct
14 Incorrect 3 ms 1236 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 3 ms 724 KB Output is correct
3 Correct 3 ms 852 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 2 ms 468 KB Output is correct
6 Correct 2 ms 724 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 2 ms 528 KB Output is correct
9 Correct 4 ms 852 KB Output is correct
10 Correct 4 ms 852 KB Output is correct
11 Correct 4 ms 852 KB Output is correct
12 Correct 9 ms 1476 KB Output is correct
13 Correct 10 ms 1576 KB Output is correct
14 Incorrect 3 ms 1236 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 3 ms 724 KB Output is correct
3 Correct 3 ms 852 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 2 ms 468 KB Output is correct
6 Correct 2 ms 724 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 2 ms 528 KB Output is correct
9 Correct 4 ms 852 KB Output is correct
10 Correct 4 ms 852 KB Output is correct
11 Correct 451 ms 38936 KB Output is correct
12 Correct 1143 ms 88088 KB Output is correct
13 Correct 712 ms 98240 KB Output is correct
14 Correct 1117 ms 78476 KB Output is correct
15 Correct 1072 ms 78488 KB Output is correct
16 Correct 1048 ms 77196 KB Output is correct
17 Correct 695 ms 97732 KB Output is correct
18 Correct 2000 ms 112060 KB Output is correct
19 Correct 2448 ms 121284 KB Output is correct
20 Correct 807 ms 76288 KB Output is correct
21 Correct 4 ms 852 KB Output is correct
22 Correct 9 ms 1476 KB Output is correct
23 Correct 10 ms 1576 KB Output is correct
24 Incorrect 3 ms 1236 KB Output isn't correct
25 Halted 0 ms 0 KB -