Submission #1105365

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105365		manhlinh1501	Nautilus (BOI19_nautilus)	C++17	100 / 100	176 ms	852 KiB

nautilus

#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
const int MAXN = 505;

int N, M, K;
bitset<MAXN> a[MAXN];
bitset<MAXN> b[MAXN];
bitset<MAXN> c[MAXN];

void update(char x) {
    if(x == 'N') {
        for(int i = 1; i <= N; i++)
            b[i] = a[i] & b[i + 1];
    }
    if(x == 'S') {
        for(int i = N; i >= 1; i--)
            b[i] = a[i] & b[i - 1];
    }
    if(x == 'E') {
        for(int i = 1; i <= N; i++)
            b[i] = a[i] & (b[i] << 1);
    }
    if(x == 'W') {
        for(int i = N; i >= 1; i--)
            b[i] = a[i] & (b[i] >> 1);
    }
    if(x == '?') {
        for(int i = 1; i <= N; i++)
            c[i] = b[i - 1] | b[i + 1] | (b[i] >> 1) | (b[i] << 1);
        for(int i = 1; i <= N; i++)
            b[i] = c[i] & a[i];
    }
}

signed main() {
#define task ""
    if(fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin >> N >> M >> K;
    for(int i = 1; i <= N; i++) {
        for(int j = 1; j <= M; j++) {
            char c = 0;
            cin >> c;
            if(c == '.') {
                a[i].set(j);
                b[i].set(j);
            }
        }
    }
    for(int i = 1; i <= K; i++) {
        char x = 0;
        cin >> x;
        update(x);
    }
    int ans = 0;
    for(int i = 1; i <= N; i++) {
        for(int j = 1; j <= M; j++) {
            if(b[i][j])
                ans++;
        }
    }
    cout << ans;
    return (0 ^ 0);
}

Compilation message (stderr)

nautilus.cpp: In function 'int main()':
nautilus.cpp:39:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
nautilus.cpp:40:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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