Submission #1078106

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078106		Neco_arc	Osmosmjerka (COCI17_osmosmjerka)	C++17	120 / 160	4061 ms	21880 KiB

osmosmjerka

#include <bits/stdc++.h>
#ifdef LOCAL
#include <bits/debug.hpp>
#endif // LOCAL

#define ll long long
#define all(x) x.begin(), x.end()
#define Neco "Osmosmjerka"
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 507

using namespace std;

const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;

const int dx[] = {0, -1, 0, 1, -1, -1, 1, 1};
const int dy[] = {-1, 0, 1, 0, -1, 1, -1, 1};

int n, m, k;
ll po[maxn * maxn];
char a[maxn][maxn];
unordered_map<ll, ll> S;

int nex(int x, int y) {
    if(x < 1) x = y;
    if(x > y) x -= y;
    return x;
}

bool inside(int i, int j) {
    return 1 <= i && i <= n && 1 <= j && j <= m;
}

ll MulHash(ll a, ll p, ll k) {
    ll ans = 0;
    for(; k > 0; k >>= 1, a = (a * p + a) % mod, p = (p * p) % mod) {
        if(k & 1) ans = (ans * p + a) % mod;
    }
    return ans;
}

ll HASH(string s) {
    ll ans = 0;
    for(char c : s) ans = (ans * base + c) % mod;
    return ans;
}

void solve()
{

    cin >> n >> m >> k;
    fi(i, 1, n) fi(j, 1, m) cin >> a[i][j];

    fi(i, 1, n) fi(j, 1, m) fi(t, 0, 7) {
        ll Hash = 0, remain = 0, len = 0;

        int u = i, v = j;
        do {
            ++len;
            Hash = (Hash * base + a[u][v]) % mod;
            u = nex(u + dx[t], n), v = nex(v + dy[t], m);

        } while(!(u == i && v == j));

        for(int u = i, v = j, _ = 1; _ <= k % len; ++_) {
            remain = (remain * base + a[u][v]) % mod;
            u = nex(u + dx[t], n), v = nex(v + dy[t], m);
        }

        Hash = MulHash(Hash, po[len], k / len);
        Hash = (Hash * po[k % len] + remain) % mod;

        S[Hash] ++;
    }


    ll mau = 1ll * m * n * 8;
    mau = mau * mau;

    ll tu = 0;
    for(auto [x, sl] : S) {
        tu = 1ll * tu + sl * sl;
    }

    ll g = __gcd(tu, mau);
    tu /= g, mau /= g;

    cout << tu << '/' << mau;

}


int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if(fopen(Neco".inp", "r")) {
        freopen(Neco".inp", "r", stdin);
        freopen(Neco".out", "w", stdout);
    }


    int nTest = 1;
//    cin >> nTest;

    po[0] = 1;
    fi(i, 1, maxn * maxn - 2) po[i] = po[i - 1] * base % mod;

    while(nTest--)
    {
        solve();
    }


    return 0;
}

Compilation message (stderr)

osmosmjerka.cpp: In function 'int main()':
osmosmjerka.cpp:110:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
osmosmjerka.cpp:111:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  111 |         freopen(Neco".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 120 / 160