oj.uz

Submission #766877

# Submission time Handle Problem Language Result Execution time Memory
766877 2023-06-26T08:28:50 Z boris_mihov Parachute rings (IOI12_rings) C++17
37 / 100
 890 ms 78580 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);

        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 (!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 11 ms 23764 KB Output is correct
2 Correct 12 ms 23960 KB Output is correct
3 Correct 13 ms 24008 KB Output is correct
4 Correct 11 ms 23832 KB Output is correct
5 Correct 12 ms 23932 KB Output is correct
6 Correct 12 ms 24140 KB Output is correct
7 Correct 12 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 12 ms 24148 KB Output is correct
10 Correct 13 ms 24148 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 280 ms 52272 KB Output is correct
2 Correct 407 ms 59668 KB Output is correct
3 Correct 163 ms 40264 KB Output is correct
4 Correct 888 ms 78580 KB Output is correct
5 Correct 854 ms 78472 KB Output is correct
6 Correct 827 ms 77220 KB Output is correct
7 Correct 149 ms 40276 KB Output is correct
8 Correct 821 ms 75064 KB Output is correct
9 Correct 890 ms 78548 KB Output is correct
10 Correct 571 ms 76324 KB Output is correct

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 23764 KB Output is correct
2 Correct 12 ms 23960 KB Output is correct
3 Correct 13 ms 24008 KB Output is correct
4 Correct 11 ms 23832 KB Output is correct
5 Correct 12 ms 23932 KB Output is correct
6 Correct 12 ms 24140 KB Output is correct
7 Correct 12 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 12 ms 24148 KB Output is correct
10 Correct 13 ms 24148 KB Output is correct
11 Incorrect 12 ms 24024 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 23764 KB Output is correct
2 Correct 12 ms 23960 KB Output is correct
3 Correct 13 ms 24008 KB Output is correct
4 Correct 11 ms 23832 KB Output is correct
5 Correct 12 ms 23932 KB Output is correct
6 Correct 12 ms 24140 KB Output is correct
7 Correct 12 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 12 ms 24148 KB Output is correct
10 Correct 13 ms 24148 KB Output is correct
11 Incorrect 12 ms 24024 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 23764 KB Output is correct
2 Correct 12 ms 23960 KB Output is correct
3 Correct 13 ms 24008 KB Output is correct
4 Correct 11 ms 23832 KB Output is correct
5 Correct 12 ms 23932 KB Output is correct
6 Correct 12 ms 24140 KB Output is correct
7 Correct 12 ms 23892 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 12 ms 24148 KB Output is correct
10 Correct 13 ms 24148 KB Output is correct
11 Correct 280 ms 52272 KB Output is correct
12 Correct 407 ms 59668 KB Output is correct
13 Correct 163 ms 40264 KB Output is correct
14 Correct 888 ms 78580 KB Output is correct
15 Correct 854 ms 78472 KB Output is correct
16 Correct 827 ms 77220 KB Output is correct
17 Correct 149 ms 40276 KB Output is correct
18 Correct 821 ms 75064 KB Output is correct
19 Correct 890 ms 78548 KB Output is correct
20 Correct 571 ms 76324 KB Output is correct
21 Incorrect 12 ms 24024 KB Output isn't correct
22 Halted 0 ms 0 KB -