Submission #542685

#	Time	Username	Problem	Language	Result	Execution time	Memory
542685		Stickfish	Nautilus (BOI19_nautilus)	C++17	100 / 100	288 ms	1100 KiB

nautilus

#include <iostream>
#include <bitset>
using namespace std;

const int MAXN = 501;
const int SZ = MAXN * MAXN;
bitset<SZ> empty_cell;
bitset<SZ> move_west;
bitset<SZ> move_east;
bitset<SZ> move_south;
bitset<SZ> ans;

signed main() {
    int r, c, m;
    cin >> r >> c >> m;
    for (int i = 0; i < r; ++i) {
        for (int j = 0; j < c; ++j) {
            char ch;
            cin >> ch;
            empty_cell[i * c + j] = (ch == '.');
            if (j)
                move_west[i * c + j] = empty_cell[i * c + j] & empty_cell[i * c + j - 1];
        }
    }
    for (int i = 0; i < r; ++i) {
        for (int j = 0; j < c; ++j) {
            if (j + 1 < c)
                move_east[i * c + j] = empty_cell[i * c + j] & empty_cell[i * c + j + 1];
            if (i + 1 < r)
                move_south[i * c + j] = empty_cell[i * c + j] & empty_cell[i * c + j + c];
        }
    }
    //cout << endl;
    ans = empty_cell;
    for (int i = 0; i < m; ++i) {
        char ch;
        cin >> ch;
        if (ch == 'N') {
            ans = (ans >> c) & empty_cell;
        } else if (ch == 'W') {
            ans = (ans & move_west) >> 1;
        } else if (ch == 'E') {
            ans = (ans & move_east) << 1;
        } else if (ch == 'S') {
            ans = (ans & move_south) << c;
        } else {
            ans = empty_cell & ((ans >> c) | ((ans & move_west) >> 1) | ((ans & move_east) << 1) | ((ans & move_south) << c));
        }
        //cout << endl;
        //for (int l = 0; l < r; ++l) {
            //for (int j = 0; j < c; ++j) {
                //cout << ans[l * c + j];
            //}
            //cout << endl;
        //}
    }
    cout << ans.count() << endl;
}

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