oj.uz

Submission #253072

# Submission time Handle Problem Language Result Execution time Memory
253072 2020-07-26T20:41:22 Z Kubin Tropical Garden (IOI11_garden) C++17
69 / 100
 5000 ms 25720 KB 
#include <functional>
#include <cstdint>
#include <cassert>
#include <vector>
#include <array>

#include <iostream>

using namespace std;

const size_t nil = SIZE_MAX;

void answer(int);

void count_routes(int _n, int _m, int _t, int E[][2], int _q, int K[])
{
    const size_t n = _n, m = _m, target = _t, q = _q;

    // get edges
    vector<array<size_t, 2>> to(n, {nil, nil});
    for(size_t i = 0; i < m; i++)
    {
        size_t u = E[i][0], v = E[i][1];
        if(to[u][0] == nil)
            to[u][0] = v;
        else if(to[u][1] == nil)
            to[u][1] = v;
        if(to[v][0] == nil)
            to[v][0] = u;
        else if(to[v][1] == nil)
            to[v][1] = u;
    }

    vector<size_t> F(2*n, nil);
    // vertex i+n is vertex after coming through best edge of vertex i
    auto nfix = [&](size_t v, size_t u) {
        return v + (to[v][0] == u ? n : 0);
    };
    for(size_t u = 0; u < n; u++)
    {
        F[u] = nfix(to[u][0], u);
        F[u+n] = nfix(to[u][1] == nil ? to[u][0] : to[u][1], u);
    }

    // rho computation
    vector<bool> vis(2*n), on(2*n);
    vector<size_t> st; st.reserve(2*n);

    vector<size_t> top(2*n, nil);
    vector<int> lambda(2*n), omega(2*n);

    vector<vector<size_t>> G(2*n);

    for(size_t s = 0; s < 2*n; s++)
    {
        G[F[s]].push_back(s);
        // cout << s << " " << F[s] << endl;
        if(vis[s])
            continue;

        assert(st.empty());
        size_t u = s;
        while(true)
        {
            vis[u] = on[u] = true;
            st.push_back(u);

            if(on[F[u]])
            {
                vector<size_t> cycle;
                while(true)
                {
                    auto v = st.back(); st.pop_back();
                    on[v] = false;
                    cycle.push_back(v);
                    if(v == F[u])
                        break;
                }
                for(auto v : cycle)
                    omega[v] = cycle.size(), top[v] = v;
            }
            else if(vis[F[u]])
            {
                lambda[u] = lambda[F[u]] + 1;
                top[u] = top[F[u]];
            }
            else
                { u = F[u]; continue; }
            break;
        }
        while(not st.empty())
        {
            auto v = st.back(); st.pop_back();
            lambda[v] = lambda[F[v]] + 1;
            top[v] = top[F[v]];
            on[v] = false;
        }
    }


    // queries

    function<pair<vector<int>, int>(size_t)> get_tab = [&](size_t t) -> pair<vector<int>, int> {
        // cout << "computing tab for t = " << t << endl;
        if(lambda[t])
        {
            // cout << " lambda" << endl;
            vector<int> cnt;
            function<void(size_t, size_t)> dfs = [&](size_t u, size_t d) {
                while(cnt.size() <= d) cnt.push_back(0);
                cnt[d] += (u < n);
                for(auto v : G[u])
                    dfs(v, d + 1);
            };
            dfs(t, 0);
            // for(auto x : cnt)
                // cout << x << " ";
            // cout << endl;
            return {cnt, 0};
        }
        else
        {
            // cout << "omega" << endl;
            size_t u = t;
            vector<int> cnt(omega[t]);
            for(int i = 0; i < omega[t]; i++, u = F[u])
            {
                int sh = (i ? omega[t] - i : 0);
                cnt[sh] += (u < n);
                sh++;
                for(auto v : G[u])
                  if(lambda[v])
                {
                    // cout << " > delegate to " << v << " shifted " << sh << endl;
                    auto [sub, _] = get_tab(v);
                    // cout << " < back to " << t << endl;
                    (void)_;
                    while(cnt.size() < sh + sub.size()) cnt.push_back(0);
                    for(size_t d = 0; d < sub.size(); d++)
                        cnt[sh + d] += sub[d];
                }
            }
            // for(auto x : cnt)
                // cout << x << " ";
            // cout << endl;
            for(size_t i = omega[t]; i < cnt.size(); i++)
                cnt[i] += cnt[i - omega[t]];
            return {cnt, omega[t]};
        }
    };

    auto count = [&](int k, size_t t) {
        auto [T, mod] = get_tab(t);
        // cout << "k = " << k << endl;
        if(mod)
        {
            while((size_t)k >= T.size())
                k -= mod;
            return T[k];
        }
        else
            return (size_t)k < T.size() ? T[k] : 0;
    };

    for(size_t que = 0; que < q; que++)
    {
        int k = K[que];
        answer(count(k, target) + count(k, target + n));
    }
}

Subtask #1
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 640 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 1 ms 768 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 3 ms 512 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 640 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 1 ms 768 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 3 ms 512 KB Output is correct
10 Correct 1 ms 384 KB Output is correct
11 Correct 12 ms 4096 KB Output is correct
12 Correct 26 ms 6528 KB Output is correct
13 Correct 47 ms 18356 KB Output is correct
14 Correct 153 ms 23416 KB Output is correct
15 Correct 156 ms 23672 KB Output is correct
16 Correct 107 ms 16888 KB Output is correct
17 Correct 99 ms 14584 KB Output is correct
18 Correct 26 ms 7032 KB Output is correct
19 Correct 138 ms 23416 KB Output is correct
20 Correct 157 ms 23672 KB Output is correct
21 Correct 105 ms 16972 KB Output is correct
22 Correct 115 ms 14584 KB Output is correct
23 Correct 109 ms 25720 KB Output is correct

Subtask #3
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 640 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 1 ms 768 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 3 ms 512 KB Output is correct
10 Correct 1 ms 384 KB Output is correct
11 Correct 12 ms 4096 KB Output is correct
12 Correct 26 ms 6528 KB Output is correct
13 Correct 47 ms 18356 KB Output is correct
14 Correct 153 ms 23416 KB Output is correct
15 Correct 156 ms 23672 KB Output is correct
16 Correct 107 ms 16888 KB Output is correct
17 Correct 99 ms 14584 KB Output is correct
18 Correct 26 ms 7032 KB Output is correct
19 Correct 138 ms 23416 KB Output is correct
20 Correct 157 ms 23672 KB Output is correct
21 Correct 105 ms 16972 KB Output is correct
22 Correct 115 ms 14584 KB Output is correct
23 Correct 109 ms 25720 KB Output is correct
24 Correct 6 ms 384 KB Output is correct
25 Correct 472 ms 4472 KB Output is correct
26 Correct 265 ms 7288 KB Output is correct
27 Execution timed out 5061 ms 19380 KB Time limit exceeded
28 Halted 0 ms 0 KB -