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Submission #317456

# Submission time Handle Problem Language Result Execution time Memory
317456 2020-10-29T18:10:41 Z mohamedsobhi777 Parachute rings (IOI12_rings) C++14
37 / 100
 1955 ms 104172 KB 
#include <bits/stdc++.h>

using namespace std;
int N;
const int cn = 1e6;

vector<int> adj[cn];
int deg[cn];
int vis[cn];
int c;
bool bd = 1;
int del;
vector<int> vec;
set<int> th;
int asy = 1;
int cs = 0;

struct dsu
{
        int fat[cn];
        dsu()
        {
                memset(fat, 0, sizeof fat);
                for (int i = 0; i < cn; ++i)
                        fat[i] = i;
        }
        inline int find(int x) { return fat[x] = (x == fat[x] ? x : find(fat[x])); }
        inline bool same(int x, int y) { return find(x) == find(y); }
        void link(int u, int v)
        {
                u = find(u);
                v = find(v);
                if (fat[u] != v)
                        fat[u] = v;
        }
} d1;

void dfs(int x, int p)
{
        vis[x] = c;
        int ch = (p != x);
        vec.push_back(x);
        for (auto u : adj[x])
        {
                if (u == p || del == u)
                        continue;
                if (vis[u] == c)
                        bd = 0;
                else
                        dfs(u, x), ++ch;
        }
        if (ch > 2)
                bd = 0;
}
set<int> bigs;

bool check(int i)
{
        del = i;
        for (auto u : adj[i])
        {
                deg[u]--;
                deg[i]--;
        }
        bool ok = 1;
        vec.clear();
        for (int j = 0; j < N; ++j)
        {
                if (vis[j] != c && i != j)
                {
                        bd = 1;
                        dfs(j, j);
                        ok &= bd;
                }
        }

        for (auto u : adj[i])
        {
                deg[u]++;
                deg[i]++;
        }
        return ok;
}

vector<int> cyc;
vector<int> now;
int onc[cn];

void detect(int x, int p)
{
        if (vis[x] == c)
        {
                cyc = now;
                for (auto u : now)
                        onc[u] = 1;
                return;
        }
        now.push_back(x);

        vis[x] = c;
        for (auto u : adj[x])
        {
                if (u == p || (int)cyc.size())
                        continue;
                detect(u, x);
        }
        now.pop_back();
}

int brute()
{
        int ret = 0;
        set<int> uni;

        if (cs > 1 || bigs.size() > 1 || th.size() > 2)
                return 0;
        if (th.size() == 0 && asy)
                return N;
        if (cs == 1 && th.size() == 0)
                return (int)cyc.size();
        if (bigs.size())
        {
                if (asy)
                        return 1;
                return onc[*bigs.begin()];
        }

        if (th.size() == 1)
        {
                if (asy)
                        return 1 + (int)adj[*th.begin()].size();
                ++c;
                set<int> anss;
                int a = (*th.begin());
                if (check(a))
                {
                        anss.insert(a);
                }
                for (auto u : adj[a])
                {
                        ++c;
                        if (check(u))
                                anss.insert(u);
                }
                return (int)anss.size();
        }
        else if (th.size() == 2)
        {

                int a = *th.begin();
                int b = *th.rbegin();
                if (cs)
                {
                        if (onc[a] + onc[b] == 0)
                                return 0;
                }
                map<int, int> mp;
                for (auto u : adj[a])
                        mp[u]++;
                for (auto u : adj[b])
                        mp[u]++;
                mp[a]++;
                mp[b]++;
                for (auto u : mp)
                {
                        if ((onc[u.first] || !cs) && u.second == 2)
                                ++ret;
                }
                return ret;
        }
        set<int> ass;
        if (th.size() == 0)
                return N;
        else
        {
                for (auto u : adj[*th.begin()])
                        ass.insert(u);
                ass.insert(*th.begin());
        }

        for (int i = 0; i < N; ++i)
        {
                ++c;
                if (check(i))
                {
                        if (th.size())
                                assert(ass.find(i) != ass.end());
                        ++ret;
                }
        }

        return ret;
}

void Init(int N_)
{

        N = N_;
}
void Link(int A, int B)
{
        adj[A].push_back(B);
        adj[B].push_back(A);
        cs += (d1.same(A, B));
        if (d1.same(A, B) && asy)
        {
                ++c;
                detect(A, A);
                asy = 0;
        }

        d1.link(A, B);
        deg[A]++;
        deg[B]++;
        if (deg[A] > 3)
                bigs.insert(A);
        if (deg[B] > 3)
                bigs.insert(B);
        if (deg[A] == 3)
        {
                th.insert(A);
        }
        if (deg[B] == 3)
        {
                th.insert(B);
        }
}

int CountCritical()
{
        if (bigs.size() > 1)
                return 0;
        return brute();
        return N;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 27776 KB Output is correct
2 Correct 20 ms 27936 KB Output is correct
3 Correct 20 ms 27904 KB Output is correct
4 Correct 21 ms 27776 KB Output is correct
5 Correct 21 ms 28032 KB Output is correct
6 Correct 21 ms 28288 KB Output is correct
7 Correct 19 ms 27776 KB Output is correct
8 Correct 20 ms 27904 KB Output is correct
9 Correct 21 ms 27904 KB Output is correct
10 Correct 23 ms 27904 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 504 ms 46136 KB Output is correct
2 Correct 981 ms 55860 KB Output is correct
3 Correct 1955 ms 79756 KB Output is correct
4 Correct 1245 ms 66064 KB Output is correct
5 Correct 1267 ms 72348 KB Output is correct
6 Correct 1376 ms 104172 KB Output is correct
7 Correct 1865 ms 80656 KB Output is correct
8 Correct 1176 ms 60792 KB Output is correct
9 Correct 1294 ms 62948 KB Output is correct
10 Correct 821 ms 65272 KB Output is correct

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 27776 KB Output is correct
2 Correct 20 ms 27936 KB Output is correct
3 Correct 20 ms 27904 KB Output is correct
4 Correct 21 ms 27776 KB Output is correct
5 Correct 21 ms 28032 KB Output is correct
6 Correct 21 ms 28288 KB Output is correct
7 Correct 19 ms 27776 KB Output is correct
8 Correct 20 ms 27904 KB Output is correct
9 Correct 21 ms 27904 KB Output is correct
10 Correct 23 ms 27904 KB Output is correct
11 Incorrect 26 ms 28032 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 27776 KB Output is correct
2 Correct 20 ms 27936 KB Output is correct
3 Correct 20 ms 27904 KB Output is correct
4 Correct 21 ms 27776 KB Output is correct
5 Correct 21 ms 28032 KB Output is correct
6 Correct 21 ms 28288 KB Output is correct
7 Correct 19 ms 27776 KB Output is correct
8 Correct 20 ms 27904 KB Output is correct
9 Correct 21 ms 27904 KB Output is correct
10 Correct 23 ms 27904 KB Output is correct
11 Incorrect 26 ms 28032 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 27776 KB Output is correct
2 Correct 20 ms 27936 KB Output is correct
3 Correct 20 ms 27904 KB Output is correct
4 Correct 21 ms 27776 KB Output is correct
5 Correct 21 ms 28032 KB Output is correct
6 Correct 21 ms 28288 KB Output is correct
7 Correct 19 ms 27776 KB Output is correct
8 Correct 20 ms 27904 KB Output is correct
9 Correct 21 ms 27904 KB Output is correct
10 Correct 23 ms 27904 KB Output is correct
11 Correct 504 ms 46136 KB Output is correct
12 Correct 981 ms 55860 KB Output is correct
13 Correct 1955 ms 79756 KB Output is correct
14 Correct 1245 ms 66064 KB Output is correct
15 Correct 1267 ms 72348 KB Output is correct
16 Correct 1376 ms 104172 KB Output is correct
17 Correct 1865 ms 80656 KB Output is correct
18 Correct 1176 ms 60792 KB Output is correct
19 Correct 1294 ms 62948 KB Output is correct
20 Correct 821 ms 65272 KB Output is correct
21 Incorrect 26 ms 28032 KB Output isn't correct
22 Halted 0 ms 0 KB -