oj.uz

Submission #411446

# Submission time Handle Problem Language Result Execution time Memory
411446 2021-05-25T11:03:18 Z KoD Parachute rings (IOI12_rings) C++17
20 / 100
 4000 ms 140132 KB 
#include <bits/stdc++.h>

template <class T>
using Vec = std::vector<T>;

struct UnionFind {
    Vec<int> par;
    UnionFind() = default;
    UnionFind(const int size): par(size, -1) { }
    int find(const int u) {
        return par[u] < 0 ? u : par[u] = find(par[u]);
    }
    int size(const int u) {
        return -par[find(u)];
    }
    bool merge(int u, int v) {
        u = find(u);
        v = find(v);
        if (u == v) return false;
        if (par[u] > par[v]) {
            std::swap(u, v);
        }
        par[u] += par[v];
        par[v] = u;
        return true;
    }
};

struct StateManager {
    UnionFind dsu;
    Vec<int> deg;
    int bad;
    bool ok;
    StateManager() = default;
    StateManager(const int size, const int bad): dsu(size), deg(size), bad(bad), ok(true) { }
    void add_edge(const int u, const int v) {
        if (u == bad or v == bad) return;
        deg[u] += 1;
        deg[v] += 1;
        if (!dsu.merge(u, v) or deg[u] >= 3 or deg[v] >= 3) {
            ok = false;
        }
    }
};

int N;
Vec<Vec<int>> adj;
Vec<std::pair<int, int>> history;
UnionFind dsu;
Vec<bool> processed;
Vec<StateManager> whatif;
Vec<std::set<int>> deglist;

/*
0: no deg >= 3, no cycles
1: no deg >= 3, one cycle
2: some deg == 3
3: one deg >= 4
-1: bad, always CountCritical() == 0
*/

int state;
int cycle_leader = -1;

void Init(int N_) {
    N = N_;
    adj.resize(N);
    dsu = UnionFind(N);
    processed = Vec<bool>(N);
    deglist = Vec<std::set<int>>(N + 5);
    for (int i = 0; i < N; ++i) {
        deglist[0].insert(i);
    }
}

void Link(int A, int B) {
    if (state == -1) return;
    deglist[adj[A].size()].erase(A);
    deglist[adj[B].size()].erase(B);
    adj[A].push_back(B);
    adj[B].push_back(A);
    deglist[adj[A].size()].insert(A);
    deglist[adj[B].size()].insert(B);
    if (deglist[4].size() >= 2) {
        state = -1;
        return;
    }
    if (!deglist[4].empty()) {
        if (state != 3) {
            state = 3;
            const auto u = *deglist[4].begin();
            whatif.clear();
            whatif.emplace_back(N, u);
            for (const auto [x, y]: history) {
                whatif[0].add_edge(x, y);
            }
        }
        whatif[0].add_edge(A, B);
    }
    else {
        if (deglist[3].size() >= 5) {
            state = -1;
            return;
        }
        if (!deglist[3].empty()) {
            state = 2;
            for (const auto u: deglist[3]) {
                if (!processed[u]) {
                    processed[u] = true;
                    whatif.emplace_back(N, u);
                    for (const auto [x, y]: history) {
                        whatif.back().add_edge(x, y);
                    }
                }
            }
            for (const auto v: deglist[3]) {
                for (const auto u: adj[v]) {
                    if (!processed[u]) {
                        processed[u] = true;
                        whatif.emplace_back(N, u);
                        for (const auto [x, y]: history) {
                            whatif.back().add_edge(x, y);
                        }
                    }
                }
            }
            for (auto& state: whatif) {
                state.add_edge(A, B);
            }
        }
        else {
            if (!dsu.merge(A, B)) {
                if (cycle_leader != -1) {
                    state = -1;
                    return;
                }
                state = 1;
                cycle_leader = dsu.find(A);
            }
        }
    }
    history.emplace_back(A, B);
}

int CountCritical() {
    if (state == 0) {
        return N;
    }
    if (state == 1) {
        return dsu.size(cycle_leader);
    }
    if (state == 2 or state == 3) {
        int ret = 0;
        for (const auto& state: whatif) {
            if (state.ok) {
                ret += 1;
            }
        }
        return ret;
    }
    return 0;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 7 ms 1100 KB Output is correct
3 Correct 10 ms 1172 KB Output is correct
4 Correct 2 ms 460 KB Output is correct
5 Correct 5 ms 844 KB Output is correct
6 Correct 9 ms 1104 KB Output is correct
7 Correct 3 ms 1484 KB Output is correct
8 Correct 5 ms 972 KB Output is correct
9 Correct 10 ms 1356 KB Output is correct
10 Correct 10 ms 1484 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2337 ms 83956 KB Output is correct
2 Execution timed out 4066 ms 140132 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 7 ms 1100 KB Output is correct
3 Correct 10 ms 1172 KB Output is correct
4 Correct 2 ms 460 KB Output is correct
5 Correct 5 ms 844 KB Output is correct
6 Correct 9 ms 1104 KB Output is correct
7 Correct 3 ms 1484 KB Output is correct
8 Correct 5 ms 972 KB Output is correct
9 Correct 10 ms 1356 KB Output is correct
10 Correct 10 ms 1484 KB Output is correct
11 Correct 8 ms 1356 KB Output is correct
12 Correct 17 ms 2948 KB Output is correct
13 Correct 16 ms 2560 KB Output is correct
14 Incorrect 6 ms 2636 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 7 ms 1100 KB Output is correct
3 Correct 10 ms 1172 KB Output is correct
4 Correct 2 ms 460 KB Output is correct
5 Correct 5 ms 844 KB Output is correct
6 Correct 9 ms 1104 KB Output is correct
7 Correct 3 ms 1484 KB Output is correct
8 Correct 5 ms 972 KB Output is correct
9 Correct 10 ms 1356 KB Output is correct
10 Correct 10 ms 1484 KB Output is correct
11 Correct 8 ms 1356 KB Output is correct
12 Correct 17 ms 2948 KB Output is correct
13 Correct 16 ms 2560 KB Output is correct
14 Incorrect 6 ms 2636 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 7 ms 1100 KB Output is correct
3 Correct 10 ms 1172 KB Output is correct
4 Correct 2 ms 460 KB Output is correct
5 Correct 5 ms 844 KB Output is correct
6 Correct 9 ms 1104 KB Output is correct
7 Correct 3 ms 1484 KB Output is correct
8 Correct 5 ms 972 KB Output is correct
9 Correct 10 ms 1356 KB Output is correct
10 Correct 10 ms 1484 KB Output is correct
11 Correct 2337 ms 83956 KB Output is correct
12 Execution timed out 4066 ms 140132 KB Time limit exceeded
13 Halted 0 ms 0 KB -