oj.uz

Submission #766887

# Submission time Handle Problem Language Result Execution time Memory
766887 2023-06-26T08:37:10 Z boris_mihov Parachute rings (IOI12_rings) C++17
37 / 100
 877 ms 78484 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;
            }

            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 12 ms 24060 KB Output is correct
3 Correct 12 ms 24036 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 24020 KB Output is correct
6 Correct 12 ms 24080 KB Output is correct
7 Correct 11 ms 23920 KB Output is correct
8 Correct 14 ms 23960 KB Output is correct
9 Correct 14 ms 24168 KB Output is correct
10 Correct 13 ms 24164 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 293 ms 52280 KB Output is correct
2 Correct 414 ms 59648 KB Output is correct
3 Correct 162 ms 40288 KB Output is correct
4 Correct 877 ms 78484 KB Output is correct
5 Correct 856 ms 78448 KB Output is correct
6 Correct 828 ms 77092 KB Output is correct
7 Correct 146 ms 40276 KB Output is correct
8 Correct 804 ms 75016 KB Output is correct
9 Correct 873 ms 78372 KB Output is correct
10 Correct 613 ms 76388 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 12 ms 24060 KB Output is correct
3 Correct 12 ms 24036 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 24020 KB Output is correct
6 Correct 12 ms 24080 KB Output is correct
7 Correct 11 ms 23920 KB Output is correct
8 Correct 14 ms 23960 KB Output is correct
9 Correct 14 ms 24168 KB Output is correct
10 Correct 13 ms 24164 KB Output is correct
11 Incorrect 16 ms 24404 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 12 ms 24060 KB Output is correct
3 Correct 12 ms 24036 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 24020 KB Output is correct
6 Correct 12 ms 24080 KB Output is correct
7 Correct 11 ms 23920 KB Output is correct
8 Correct 14 ms 23960 KB Output is correct
9 Correct 14 ms 24168 KB Output is correct
10 Correct 13 ms 24164 KB Output is correct
11 Incorrect 16 ms 24404 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 12 ms 24060 KB Output is correct
3 Correct 12 ms 24036 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 24020 KB Output is correct
6 Correct 12 ms 24080 KB Output is correct
7 Correct 11 ms 23920 KB Output is correct
8 Correct 14 ms 23960 KB Output is correct
9 Correct 14 ms 24168 KB Output is correct
10 Correct 13 ms 24164 KB Output is correct
11 Correct 293 ms 52280 KB Output is correct
12 Correct 414 ms 59648 KB Output is correct
13 Correct 162 ms 40288 KB Output is correct
14 Correct 877 ms 78484 KB Output is correct
15 Correct 856 ms 78448 KB Output is correct
16 Correct 828 ms 77092 KB Output is correct
17 Correct 146 ms 40276 KB Output is correct
18 Correct 804 ms 75016 KB Output is correct
19 Correct 873 ms 78372 KB Output is correct
20 Correct 613 ms 76388 KB Output is correct
21 Incorrect 16 ms 24404 KB Output isn't correct
22 Halted 0 ms 0 KB -