Submission #713288

#	Time	Username	Problem	Language	Result	Execution time	Memory
713288		Johann	Osmosmjerka (COCI17_osmosmjerka)	C++14	140 / 160	2483 ms	262144 KiB

osmosmjerka

#include "bits/stdc++.h"
using namespace std;

typedef long long ll;
typedef pair<ll, ll> pii;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vvvi> vvvvi;
typedef vector<pii> vpii;
#define sz(x) (ll)(x).size()
#define all(x) (x).begin(), (x).end()

const ll MOD = ((1LL << 61) - 1);
const ll P = 9973;
const ll P1 = 98999;
const ll P2 = 22573;
const ll P3 = 1367;
const ll P4 = 41809;
ll mod_mul(ll a, ll b)
{
    __int128 res = (__int128)a * b;
    return res % MOD;
}

int N, M, K;
vpii dirs = {{1, 1}, {1, 0}, {1, -1}, {0, 1}, {0, -1}, {-1, 1}, {-1, 0}, {-1, -1}};
pii move(pii &pos, pii &dir, ll amount)
{
    pii ans;
    ans.first = (pos.first + dir.first * amount) % N;
    ans.second = (pos.second + dir.second * amount) % M;
    ans.first = (ans.first + N) % N;
    ans.second = (ans.second + M) % M;
    assert(0 <= ans.first && 0 <= ans.second && ans.first < N && ans.second < M);
    return ans;
}
vvi grid;
vvvvi dp;
vi pot;

void initDP()
{
    int logheight = ceil(log2(K) + 1);
    dp.assign(N, vvvi(M, vvi(sz(dirs), vi(logheight, 0))));
    for (int i = 0; i < N; ++i)
        for (int j = 0; j < M; ++j)
            for (int d = 0; d < sz(dirs); ++d)
                dp[i][j][d][0] = grid[i][j];

    pot.assign(logheight, P); // pot[i] = P^(2^i)
    for (int l = 1; l < logheight; ++l)
    {
        pot[l] = mod_mul(pot[l - 1], pot[l - 1]);
        for (int i = 0; i < N; ++i)
            for (int j = 0; j < M; ++j)
            {
                pii coords = {i, j};
                ll in, jn;
                for (int d = 0; d < sz(dirs); ++d)
                {
                    tie(in, jn) = move(coords, dirs[d], 1LL << (l - 1));
                    dp[i][j][d][l] = (dp[i][j][d][l - 1] + mod_mul(pot[l - 1], dp[in][jn][d][l - 1])) % MOD;
                    assert(dp[i][j][d][l] >= 0);
                }
            }
    }
}

ll lift(pii pos, int d, int k)
{
    int i, j;
    tie(i, j) = pos;
    ll ans = 0;
    ll pp = 1;
    for (int l = 0; l < sz(dp[i][j][d]); ++l)
    {
        if (k & (1 << l))
        {
            ans = (ans + mod_mul(pp, dp[i][j][d][l])) % MOD;
            pp = mod_mul(pp, pot[l]);
            tie(i, j) = move(pos, dirs[d], 1LL << l);
        }
        assert(ans >= 0);
    }
    return ans;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> N >> M >> K;

    grid.assign(N, vi(M, 0));
    for (int i = 0; i < N; ++i)
    {
        string tmp;
        cin >> tmp;
        for (int j = 0; j < M; ++j)
            grid[i][j] = tmp[j];
    }

    initDP();

    vi paths;
    for (int i = 0; i < N; ++i)
        for (int j = 0; j < M; ++j)
            for (int d = 0; d < sz(dirs); ++d)
                paths.push_back(lift({i, j}, d, K));
    sort(all(paths));

    ll num = 0;
    ll denom = sz(paths) * sz(paths);

    ll last = paths.front();
    ll cnt = 1;
    for (int i = 1; i < sz(paths); ++i)
    {
        if (paths[i] == last)
            ++cnt;
        else
        {
            num += cnt * cnt;
            cnt = 1;
            last = paths[i];
        }
    }
    num += cnt * cnt;

    ll g = __gcd(num, denom);

    cout << num / g << "/" << denom / g << endl;

    return 0;
}

• Subtask 1: 140 / 160