Submission #1269065

#	Time	Username	Problem	Language	Result	Execution time	Memory
1269065		ducdev	Nautilus (BOI19_nautilus)	C++17	100 / 100	130 ms	800 KiB

nautilus

// Author: 4uckd3v - Nguyen Cao Duc
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const int MAX_N = 500;
const int MAX_K = 5000;
const int MOD = 1e9 + 7;

int m, n, k;
string dir;
bitset<MAX_N + 5> nxt[MAX_N + 5], cur[MAX_N + 5], ban[MAX_N + 5], mask;
char a[MAX_N + 5][MAX_N + 5];

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if (fopen("MAIN.INP", "r")) {
        freopen("MAIN.INP", "r", stdin);
        freopen("MAIN.OUT", "w", stdout);
    };

    cin >> m >> n >> k;
    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            cin >> a[i][j];
            if (a[i][j] == '.')
                cur[i].set(j);
            else
                ban[i].set(j);
        };
    };

    cin >> dir;
    dir = " " + dir;

    for (int i = 1; i <= n; i++) mask.set(i);

    int res = 0;

    for (int i = 1; i <= k; i++) {
        for (int j = 1; j <= m; j++) nxt[j].reset();
        for (int j = 1; j <= m; j++) {
            if (dir[i] == 'W' || dir[i] == '?') nxt[j] |= (cur[j] >> 1);
            if (dir[i] == 'E' || dir[i] == '?') nxt[j] |= (cur[j] << 1);
            if (dir[i] == 'S' || dir[i] == '?') nxt[j] |= cur[j - 1];
            if (dir[i] == 'N' || dir[i] == '?') nxt[j] |= cur[j + 1];
            nxt[j] &= mask;
            nxt[j] &= ~ban[j];
        };
        for (int j = 1; j <= m; j++) swap(nxt[j], cur[j]);
    };

    for (int i = 1; i <= m; i++) res += cur[i].count();

    cout << res << '\n';
};

Compilation message (stderr)

nautilus.cpp: In function 'int main()':
nautilus.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen("MAIN.INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
nautilus.cpp:21:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |         freopen("MAIN.OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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