oj.uz

Submission #253066

# Submission time Handle Problem Language Result Execution time Memory
253066 2020-07-26T20:10:00 Z Kubin Tropical Garden (IOI11_garden) C++17
49 / 100
 5000 ms 9836 KB 
#include <cstdint>
#include <cassert>
#include <vector>
#include <array>


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);

    for(size_t s = 0; s < 2*n; s++)
    {
        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;
        }
    }

    auto count = [&](int k, size_t t) {
        int result = 0;
        for(size_t u = 0; u < n; u++)
        {
            size_t v = u;
            int l = k;
            while(l)
            {
                if(not lambda[v] and l >= omega[v])
                    l %= omega[v];
                else if(lambda[v] and l >= lambda[v])
                    l -= lambda[v], v = top[v];
                else
                    v = F[v], l--;
            }
            if(v == t)
                result++;
        }
        return result;
    };

    // queries
    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 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 256 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 0 ms 256 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 3 ms 384 KB Output is correct

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 256 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 0 ms 256 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 3 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 202 ms 2048 KB Output is correct
12 Correct 357 ms 3320 KB Output is correct
13 Execution timed out 5063 ms 9836 KB Time limit exceeded
14 Halted 0 ms 0 KB -

Subtask #3
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 256 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 0 ms 256 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 3 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 202 ms 2048 KB Output is correct
12 Correct 357 ms 3320 KB Output is correct
13 Execution timed out 5063 ms 9836 KB Time limit exceeded
14 Halted 0 ms 0 KB -