oj.uz

Submission #766898

# Submission time Handle Problem Language Result Execution time Memory
766898 2023-06-26T08:41:17 Z boris_mihov Parachute rings (IOI12_rings) C++17
37 / 100
 922 ms 79008 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();
    toNode2.clear();
    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 && i != node)
        {
            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;
            }

            assert(cntThree > 1);
            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 23764 KB Output is correct
2 Correct 11 ms 24048 KB Output is correct
3 Correct 16 ms 24020 KB Output is correct
4 Correct 14 ms 23844 KB Output is correct
5 Correct 15 ms 24004 KB Output is correct
6 Correct 14 ms 24148 KB Output is correct
7 Correct 10 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 11 ms 24124 KB Output is correct
10 Correct 11 ms 24152 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 280 ms 52244 KB Output is correct
2 Correct 411 ms 59696 KB Output is correct
3 Correct 175 ms 40296 KB Output is correct
4 Correct 876 ms 78888 KB Output is correct
5 Correct 900 ms 79008 KB Output is correct
6 Correct 858 ms 77588 KB Output is correct
7 Correct 161 ms 40300 KB Output is correct
8 Correct 841 ms 75516 KB Output is correct
9 Correct 922 ms 78780 KB Output is correct
10 Correct 610 ms 76672 KB Output is correct

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 23764 KB Output is correct
2 Correct 11 ms 24048 KB Output is correct
3 Correct 16 ms 24020 KB Output is correct
4 Correct 14 ms 23844 KB Output is correct
5 Correct 15 ms 24004 KB Output is correct
6 Correct 14 ms 24148 KB Output is correct
7 Correct 10 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 11 ms 24124 KB Output is correct
10 Correct 11 ms 24152 KB Output is correct
11 Incorrect 14 ms 24268 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 23764 KB Output is correct
2 Correct 11 ms 24048 KB Output is correct
3 Correct 16 ms 24020 KB Output is correct
4 Correct 14 ms 23844 KB Output is correct
5 Correct 15 ms 24004 KB Output is correct
6 Correct 14 ms 24148 KB Output is correct
7 Correct 10 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 11 ms 24124 KB Output is correct
10 Correct 11 ms 24152 KB Output is correct
11 Incorrect 14 ms 24268 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 23764 KB Output is correct
2 Correct 11 ms 24048 KB Output is correct
3 Correct 16 ms 24020 KB Output is correct
4 Correct 14 ms 23844 KB Output is correct
5 Correct 15 ms 24004 KB Output is correct
6 Correct 14 ms 24148 KB Output is correct
7 Correct 10 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 11 ms 24124 KB Output is correct
10 Correct 11 ms 24152 KB Output is correct
11 Correct 280 ms 52244 KB Output is correct
12 Correct 411 ms 59696 KB Output is correct
13 Correct 175 ms 40296 KB Output is correct
14 Correct 876 ms 78888 KB Output is correct
15 Correct 900 ms 79008 KB Output is correct
16 Correct 858 ms 77588 KB Output is correct
17 Correct 161 ms 40300 KB Output is correct
18 Correct 841 ms 75516 KB Output is correct
19 Correct 922 ms 78780 KB Output is correct
20 Correct 610 ms 76672 KB Output is correct
21 Incorrect 14 ms 24268 KB Output isn't correct
22 Halted 0 ms 0 KB -