Submission #1187592

#	Time	Username	Problem	Language	Result	Execution time	Memory
1187592		omerking	Nautilus (BOI19_nautilus)	C++20	100 / 100	209 ms	832 KiB

nautilus

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define endl "\n"
using namespace std;
using namespace __gnu_pbds;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T, typename key = less<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
const ll N = 505;
string s[N];
bitset<N> bs[N], nbs[N], good[N];
ll n, m, k;
void solve()
{
    cin >> n >> m >> k;
    for (ll i = 1; i <= n; i++) 
    {
        cin >> s[i];
        s[i] = "#" + s[i];
    }
    string dir;
    cin >> dir;
    dir = ' ' + dir;
    for (ll i = 1; i <= n; i++)
    for (ll j = 1; j <= m; j++) bs[i][j] = good[i][j] = s[i][j] != '#';
    for (ll x = 1; x <= k; x++)
    {
        for (ll i = 1; i <= n; i++) nbs[i] = 0;
        if (dir[x] == 'N')
        {
            for (ll i = 1; i < n; i++) nbs[i] = bs[i + 1] & good[i];
        }
        else if (dir[x] == 'S')
        {
            for (ll i = 2; i <= n; i++) nbs[i] = bs[i - 1] & good[i];
        }
        else if (dir[x] == 'E')
        {
            for (ll i = 1; i <= n; i++) nbs[i] = (bs[i] << 1) & good[i];
        }
        else if (dir[x] == 'W')
        {
            for (ll i = 1; i <= n; i++) nbs[i] = (bs[i] >> 1) & good[i];
        }
        else
        {
            for (ll i = 1; i <= n; i++) nbs[i] = (bs[i - 1] | bs[i + 1] | (bs[i] << 1) | (bs[i] >> 1)) & good[i];
        }
        for (ll i = 1; i <= n; i++) bs[i] = nbs[i];
    }
    ll ans = 0;
    for (ll i = 1; i <= n; i++) ans += bs[i].count();
    cout << ans << endl;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll t = 1;
    for (ll cs = 1; cs <= t; cs++)
        solve();
}

• Subtask 1: 29 / 29
• Subtask 2: 37 / 37
• Subtask 3: 34 / 34