Submission #1125605

#	Time	Username	Problem	Language	Result	Execution time	Memory
1125605		thinknoexit	Nautilus (BOI19_nautilus)	C++20	100 / 100	122 ms	536 KiB

nautilus

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
bitset<505> a[505];
bitset<505> dp[2][505];
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n, m, Q;
    cin >> n >> m >> Q;
    for (int i = 1;i <= n;i++) {
        for (int j = 1;j <= m;j++) {
            char t;
            cin >> t;
            a[i][j] = (t == '.');
        }
    }
    for (int i = 1;i <= n;i++) dp[0][i] = a[i];
    for (int st = 1;st <= Q;st++) {
        int now = st & 1, prev = 1 - now;
        //
        char c;
        cin >> c;
        if (c == 'N') {
            for (int i = 1;i < n;i++) {
                dp[now][i] = dp[prev][i + 1] & a[i];
            }
            dp[now][n].reset();
        }
        else if (c == 'S') {
            for (int i = 2;i <= n;i++) {
                dp[now][i] = dp[prev][i - 1] & a[i];
            }
            dp[now][1].reset();
        }
        else if (c == 'E') {
            for (int i = 1;i <= n;i++) {
                dp[now][i] = (dp[prev][i] << 1) & a[i];
            }
        }
        else if (c == 'W') {
            for (int i = 1;i <= n;i++) {
                dp[now][i] = (dp[prev][i] >> 1) & a[i];
            }
        }
        else {
            for (int i = 1;i <= n;i++) {
                dp[now][i].reset();
                dp[now][i] |= dp[prev][i - 1];
                dp[now][i] |= dp[prev][i + 1];
                dp[now][i] |= dp[prev][i] >> 1;
                dp[now][i] |= dp[prev][i] << 1;
                dp[now][i] &= a[i];
            }
        }
    }
    int ans = 0;
    for (int i = 1;i <= n;i++) {
        ans += dp[Q & 1][i].count();
    }
    cout << ans << '\n';
    return 0;
}
/*
5 9 7
...##....
..#.##..#
..#....##
.##...#..
....#....
WS?EE??
*/

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