Submission #1201171

#	Time	Username	Problem	Language	Result	Execution time	Memory
1201171		browntoad	Nautilus (BOI19_nautilus)	C++20	100 / 100	177 ms	992 KiB

nautilus

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<typename T>
using pbds_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define ll long long
#define int ll
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) for (int i = (n)-1; i >= 0; i--)
#define RREP1(i, n) for (int i = (n); i >= 1; i--)
#define REP1(i, n) FOR(i, 1, n+1)
#define pii pair<int, int>
#define ppi pair<pii, int>
#define pip pair<int, pii>
#define f first
#define s second
#define pb push_back
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) (int)((x).size())
#define endl '\n'
#define IOS() ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)

const ll maxn = 505;
const ll mod = 998244353;
const ll inf = (1ll<<60);
const int iinf = 1e9+5;

ll pw(ll x, ll p, ll m){
    ll ret = 1;
    x %= m;
    while(p > 0){
        if (p & 1){
            ret *= x;
            ret %= m;
        }
        x *= x;
        x %= m;
        p >>= 1;
    }
    return ret;
}
ll inv(ll x, ll m){
    return pw(x, m-2, m);
}

bitset<maxn> dp[2][maxn]; // by row
bitset<maxn> death[maxn];

int n, m, k;
char arr[maxn][maxn];

vector<int> dx = {1, 0, -1, 0};
vector<int> dy = {0, 1, 0, -1};
vector<char> can = {'N', 'W', 'S', 'E'};
signed main(){
    IOS();
    cin>>n>>m>>k;
    REP1(i, n){
        REP1(j, m){
            cin>>arr[i][j];
            if (arr[i][j] == '.') {
                dp[0][i][j] = 1;
                death[i][j] = 1;
            }
        }
    }

    string toad; cin>>toad;
    REP1(t, k){
        bool b = (t&1); bool ob = (b^1);
        REP1(i, n) dp[b][i] = 0;
        if (toad[t-1] == 'N' || toad[t-1] == '?'){
            REP1(i, n-1){
                dp[b][i] |= dp[ob][i+1];
            }
        }
        if (toad[t-1] == 'S' || toad[t-1] == '?'){
            FOR(i, 2, n+1){
                dp[b][i] |= dp[ob][i-1];
            }
        }
        if (toad[t-1] == 'W' || toad[t-1] == '?'){
            REP1(i, n) dp[b][i] |= (dp[ob][i]>>1);
        }
        if (toad[t-1] == 'E' || toad[t-1] == '?'){
            REP1(i, n) dp[b][i] |= (dp[ob][i]<<1);
        }

        REP1(i, n) dp[b][i] &= death[i];
    }
    int sm = 0;
    REP1(i, n){
        REP1(j, m){
            sm += dp[k&1][i][j];
        }
    }
    cout<<sm<<endl;

}
/*
5 9 1
...##....
..#.##..#
..#....##
.##...#..
....#....
?
*/

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