oj.uz

Submission #766873

# Submission time Handle Problem Language Result Execution time Memory
766873 2023-06-26T08:25:46 Z boris_mihov Parachute rings (IOI12_rings) C++17
37 / 100
 793 ms 78572 KB 
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <set>

typedef long long llong;
const int MAXN = 1000000 + 10;
const int INF  = 1e9;

int n;
int d[MAXN];
struct DSU
{
    int par[MAXN];
    int dep[MAXN];
    int sz[MAXN];

    void build()
    {
        for (int i = 1 ; i <= n ; ++i)
        {
            par[i] = i;
            dep[i] = 1;
            sz[i] = 1;
        }
    }

    int find(int u)
    {
        if (u == par[u]) return u;
        return par[u] = find(par[u]);
    }

    void connect(int u, int v)
    {
        u = find(u);
        v = find(v);

        if (u == v)
        {
            assert(false);
            return;
        }

        if (dep[u] < dep[v])
        {
            std::swap(u, v);
        }

        if (dep[u] == dep[v])
        {
            dep[v]++;
        }

        par[u] = v;
        sz[v] += sz[u];
    }

    bool areConnected(int u, int v)
    {
        return find(u) == find(v);
    }
};

DSU dsu;
int ans;
void Init(int N_) 
{
    n = N_;
    ans = n;
    dsu.build();
}

int cycle;
bool isBad;
int cntThree;
int theNode = -1;
std::set <int> toNode;
std::vector <int> three;
std::vector <std::pair <int,int>> added;
std::vector <int> g[MAXN];

void reConnect(int node)
{
    dsu.build();
    theNode = node;
    std::fill(d + 1, d + 1 + n, 0);
    for (const auto &[u, v] : added)
    {
        d[u]++;
        d[v]++;
        if (u == node)
        {
            toNode.insert(v);
            continue;
        }

        if (v == node)
        {
            toNode.insert(u);
            continue;
        }

        if (dsu.areConnected(u, v))
        {
            isBad = true;
            return;
        }

        dsu.connect(u, v);
    }

    for (int i = 1 ; i <= n ; ++i)
    {
        if (d[i] - toNode.count(i) > 2 && i != node)
        {
            isBad = true;
            return;
        }
    }
}

void Link(int u, int v)
{
    u++;
    v++;
    if (isBad)
    {
        return;
    }

    added.push_back({u, v});
    if (theNode != -1)
    {
        if (v == theNode)
        {
            std::swap(u, v);
        }

        if (u == theNode)
        {
            d[v]++;
            toNode.insert(v);
            if (d[v] > 3)
            {
                isBad = true;
                return;
            }
        } else
        {
            d[v]++;
            d[u]++;
            if (d[v] - toNode.count(v) > 2)
            {
                isBad = true;
                return;
            }

            if (d[u] - toNode.count(u) > 2)
            {
                isBad = true;
                return;
            }

            if (dsu.areConnected(u, v))
            {
                isBad = true;
                return;
            }

            dsu.connect(u, v);
        }
    } else
    {
        d[u]++;
        d[v]++;
        if (d[u] == 4 && d[v] == 4)
        {
            isBad = true;
            return;
        }

        if (d[u] == 4)
        {
            reConnect(u);
            return;
        }

        if (d[v] == 4)
        {
            reConnect(v);
            return;
        }

        cntThree += (d[u] == 3);
        cntThree += (d[v] == 3);

        if (cycle && dsu.areConnected(u, v))
        {
            if (dsu.find(u) != dsu.find(cycle))
            {
                isBad = true;
                return;
            }
        }

        if (!cycle && dsu.areConnected(u, v))
        {
            cycle = dsu.find(u);
        }

        if (!dsu.areConnected(u, v))
        {
            dsu.connect(u, v);
        }

        g[u].push_back(v);
        g[v].push_back(u);

        if (d[u] == 3)
        {
            three.push_back(u);
        }

        if (d[v] == 3)
        {
            three.push_back(v);
        }

        if (cycle)
        {
            if (cntThree > 2)
            {
                isBad = true;
                return;
            }

            for (const int &u : three)
            {
                if (dsu.find(u) != dsu.find(cycle))
                {
                    isBad = true;
                    return;
                }
            }

            if (cntThree == 0)
            {
                ans = dsu.sz[dsu.find(cycle)];
                return;
            }

            if (cntThree == 1)
            {
                ans = 3;
                return;
            }

            ans = 2;
            return;
        }

        if (cntThree > 4)
        {
            isBad = true;
            return;
        }

        if (cntThree == 0)
        {
            ans = n;
            return;
        }

        if (cntThree == 1)
        {
            ans = 4;
            return;
        }

        ans = 0;
        for (const int &i : three)
        {
            int curr = 0;
            for (const int &u : g[i])
            {
                curr += (d[u] == 3);
            }

            if (curr == cntThree - 1)
            {
                ans++;
            }
        }

        if (cntThree == 2)
        {
            for (const int &u : g[three[0]])
            {
                for (const int &v : g[three[1]])
                {
                    if (u == v)
                    {
                        ans++;
                    }
                }
            }
        }
    }
}

int CountCritical() 
{
    if (isBad) return 0;
    assert(ans != 0);
    if (theNode != -1) return 1;
    return ans;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 24020 KB Output is correct
3 Correct 14 ms 24020 KB Output is correct
4 Correct 11 ms 23764 KB Output is correct
5 Correct 11 ms 24012 KB Output is correct
6 Correct 13 ms 24104 KB Output is correct
7 Correct 11 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 24044 KB Output is correct
10 Correct 13 ms 24092 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 269 ms 52260 KB Output is correct
2 Correct 366 ms 59616 KB Output is correct
3 Correct 161 ms 40332 KB Output is correct
4 Correct 779 ms 78488 KB Output is correct
5 Correct 776 ms 78572 KB Output is correct
6 Correct 770 ms 77088 KB Output is correct
7 Correct 149 ms 40268 KB Output is correct
8 Correct 730 ms 74956 KB Output is correct
9 Correct 793 ms 78352 KB Output is correct
10 Correct 545 ms 76284 KB Output is correct

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 24020 KB Output is correct
3 Correct 14 ms 24020 KB Output is correct
4 Correct 11 ms 23764 KB Output is correct
5 Correct 11 ms 24012 KB Output is correct
6 Correct 13 ms 24104 KB Output is correct
7 Correct 11 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 24044 KB Output is correct
10 Correct 13 ms 24092 KB Output is correct
11 Incorrect 13 ms 24148 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 24020 KB Output is correct
3 Correct 14 ms 24020 KB Output is correct
4 Correct 11 ms 23764 KB Output is correct
5 Correct 11 ms 24012 KB Output is correct
6 Correct 13 ms 24104 KB Output is correct
7 Correct 11 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 24044 KB Output is correct
10 Correct 13 ms 24092 KB Output is correct
11 Incorrect 13 ms 24148 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 24020 KB Output is correct
3 Correct 14 ms 24020 KB Output is correct
4 Correct 11 ms 23764 KB Output is correct
5 Correct 11 ms 24012 KB Output is correct
6 Correct 13 ms 24104 KB Output is correct
7 Correct 11 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 24044 KB Output is correct
10 Correct 13 ms 24092 KB Output is correct
11 Correct 269 ms 52260 KB Output is correct
12 Correct 366 ms 59616 KB Output is correct
13 Correct 161 ms 40332 KB Output is correct
14 Correct 779 ms 78488 KB Output is correct
15 Correct 776 ms 78572 KB Output is correct
16 Correct 770 ms 77088 KB Output is correct
17 Correct 149 ms 40268 KB Output is correct
18 Correct 730 ms 74956 KB Output is correct
19 Correct 793 ms 78352 KB Output is correct
20 Correct 545 ms 76284 KB Output is correct
21 Incorrect 13 ms 24148 KB Output isn't correct
22 Halted 0 ms 0 KB -