oj.uz

Submission #766886

# Submission time Handle Problem Language Result Execution time Memory
766886 2023-06-26T08:36:53 Z boris_mihov Parachute rings (IOI12_rings) C++17
37 / 100
 876 ms 78656 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];
int d2[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;
DSU dsu2;
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::set <int> toNode2;
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;
        }
    }
}

bool check(int node)
{
    dsu2.build();
    std::fill(d2 + 1, d2 + 1 + n, 0);
    for (const auto &[u, v] : added)
    {
        d2[u]++;
        d2[v]++;
        if (u == node)
        {
            toNode2.insert(v);
            continue;
        }

        if (v == node)
        {
            toNode2.insert(u);
            continue;
        }

        if (dsu2.areConnected(u, v))
        {
            return false;
        }

        dsu2.connect(u, v);
    }

    for (int i = 1 ; i <= n ; ++i)
    {
        if (d2[i] - toNode2.count(i) > 2)
        {
            return false;
        }
    }

    return true;
}

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);

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

            if (!check(three[0]))
            {
                isBad = true;
                return;
            }
        }

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

        if (!dsu.areConnected(u, v))
        {
            dsu.connect(u, 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 == 2)
            {
                bool good = false;
                for (const int &i : g[three[0]])
                {   
                    if (i == three[1])
                    {
                        good = true;
                    }
                }

                if (!good)
                {
                    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;
    if (theNode != -1) return 1;
    return ans;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23784 KB Output is correct
2 Correct 14 ms 23988 KB Output is correct
3 Correct 12 ms 24020 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 24032 KB Output is correct
6 Correct 12 ms 24168 KB Output is correct
7 Correct 11 ms 23904 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 24148 KB Output is correct
10 Correct 12 ms 24060 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 268 ms 52248 KB Output is correct
2 Correct 433 ms 59652 KB Output is correct
3 Correct 158 ms 40276 KB Output is correct
4 Correct 870 ms 78656 KB Output is correct
5 Correct 855 ms 78500 KB Output is correct
6 Correct 876 ms 77152 KB Output is correct
7 Correct 147 ms 40340 KB Output is correct
8 Correct 803 ms 75020 KB Output is correct
9 Correct 865 ms 78408 KB Output is correct
10 Correct 577 ms 76304 KB Output is correct

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23784 KB Output is correct
2 Correct 14 ms 23988 KB Output is correct
3 Correct 12 ms 24020 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 24032 KB Output is correct
6 Correct 12 ms 24168 KB Output is correct
7 Correct 11 ms 23904 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 24148 KB Output is correct
10 Correct 12 ms 24060 KB Output is correct
11 Incorrect 12 ms 24264 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23784 KB Output is correct
2 Correct 14 ms 23988 KB Output is correct
3 Correct 12 ms 24020 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 24032 KB Output is correct
6 Correct 12 ms 24168 KB Output is correct
7 Correct 11 ms 23904 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 24148 KB Output is correct
10 Correct 12 ms 24060 KB Output is correct
11 Incorrect 12 ms 24264 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23784 KB Output is correct
2 Correct 14 ms 23988 KB Output is correct
3 Correct 12 ms 24020 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 24032 KB Output is correct
6 Correct 12 ms 24168 KB Output is correct
7 Correct 11 ms 23904 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 24148 KB Output is correct
10 Correct 12 ms 24060 KB Output is correct
11 Correct 268 ms 52248 KB Output is correct
12 Correct 433 ms 59652 KB Output is correct
13 Correct 158 ms 40276 KB Output is correct
14 Correct 870 ms 78656 KB Output is correct
15 Correct 855 ms 78500 KB Output is correct
16 Correct 876 ms 77152 KB Output is correct
17 Correct 147 ms 40340 KB Output is correct
18 Correct 803 ms 75020 KB Output is correct
19 Correct 865 ms 78408 KB Output is correct
20 Correct 577 ms 76304 KB Output is correct
21 Incorrect 12 ms 24264 KB Output isn't correct
22 Halted 0 ms 0 KB -