Submission #450025

#	Time	Username	Problem	Language	Result	Execution time	Memory
450025		zxcvbnm	Nautilus (BOI19_nautilus)	C++14	100 / 100	186 ms	157420 KiB

nautilus

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
bitset<505> dp[505][5005], sea[505];
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, m, k;
    cin >> n >> m >> k;
    char mat[n][m];
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cin >> mat[i][j];
        }
    }
    string str;
    cin >> str;

    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            sea[i][j] = mat[i][j] == '.';
        }
    }

    for(int i = 0; i < n; i++) {
        dp[i][0] = sea[i];
    }

    for(int t = 0; t < k; t++) {
        if (str[t] == 'N') {
            for(int i = 0; i < n; i++) {
                dp[i][t+1] = dp[i+1][t] & sea[i];
            }
        } else if (str[t] == 'S') {
            for(int i = 1; i < n; i++) {
                dp[i][t+1] = dp[i-1][t] & sea[i];
            }
        } else if (str[t] == 'E') {
            for(int i = 0; i < n; i++) {
                dp[i][t+1] = (dp[i][t] << 1) & sea[i];
            }
        } else if (str[t] == 'W') {
            for(int i = 0; i < n; i++) {
                dp[i][t+1] = (dp[i][t] >> 1) & sea[i];
            }
        } else if (str[t] == '?') {
            for(int i = 0; i < n; i++) {
                dp[i][t+1] = ((i+1 < n ? dp[i+1][t] : 0) |
                             (i-1 >= 0 ? dp[i-1][t] : 0) |
                             (dp[i][t] >> 1) |
                             (dp[i][t] << 1)) &
                             sea[i];
            }
        }
    }

    int ans = 0;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            ans += dp[i][k][j];
        }
    }
    cout << ans << "\n";
    return 0;
}

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