Submission #687493

#	Time	Username	Problem	Language	Result	Execution time	Memory
687493		stanislavpolyn	Nautilus (BOI19_nautilus)	C++17	0 / 100	2 ms	468 KiB

nautilus

#include <bits/stdc++.h>

#define fr(i, a, b) for (int i = (a); i <= (b); ++i)
#define rf(i, a, b) for (int i = (a); i >= (b); --i)
#define fe(x, y) for (auto& x : y)

#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define mt make_tuple

#define all(x) (x).begin(), (x).end()
#define pw(x) (1LL << (x))
#define sz(x) (int)(x).size()

using namespace std;

mt19937_64 rng(228);

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define fbo find_by_order
#define ook order_of_key

template <typename T>
bool umn(T& a, T b) {
    return a > b ? a = b, 1 : 0;
}
template <typename T>
bool umx(T& a, T b) {
    return a < b ? a = b, 1 : 0;
}

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template <typename T>
using ve = vector<T>;

const int N = 505;

const int dx[] = {1 -1, 0, 0};
const int dy[] = {0, 0, 1, -1};
const string d = "SNEW";

int n, m, k;
char a[N][N];
string s;

bool dp[N][N], ndp[N][N];

bool valid(int x, int y) {
    return x >= 1 && y >= 1 && x <= n && y <= m && a[x][y] != '#';
}

int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    ios::sync_with_stdio(0);
    cin.tie(0);
#endif

    cin >> n >> m >> k;

    fr (i, 1, n) {
        fr (j, 1, m) {
            cin >> a[i][j];
        }
    }

    cin >> s;

    fr (i, 1, n) {
        fr (j, 1, m) {
            if (a[i][j] != '#') {
                dp[i][j] = 1;
            }
        }
    }

    fr (step, 0, sz(s) - 1) {
        int p = find(all(d), s[step]) - d.begin();


        fr (i, 1, n) {
            fr (j, 1, m) {
                if (dp[i][j]) {
                    if (p != sz(d)) {
                        if (valid(i + dx[p], j + dy[p])) {
                            ndp[i + dx[p]][j + dy[p]] = 1;
                        }
                    } else {
                        fr (cur, 0, 3) {
                            if (valid(i + dx[cur], j + dy[cur])) {
                                ndp[i + dx[cur]][j + dy[cur]] = 1;
                            }
                        }
                    }
                }
            }
        }
        fr (i, 1, n) {
            fr (j, 1, m) {
                dp[i][j] = ndp[i][j];
                ndp[i][j] = 0;
            }
        }
    }

    int ans = 0;
    fr (i, 1, n) {
        fr (j, 1, m) {
            if (dp[i][j]) {
                ans++;
            }
        }
    }
    cout << ans << "\n";

    return 0;
}

Compilation message (stderr)

nautilus.cpp: In function 'int main()':
nautilus.cpp:100:49: warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]
  100 |                             if (valid(i + dx[cur], j + dy[cur])) {
      |                                           ~~~~~~^
nautilus.cpp:3:41: note: within this loop
    3 | #define fr(i, a, b) for (int i = (a); i <= (b); ++i)
      |                                         ^
nautilus.cpp:99:25: note: in expansion of macro 'fr'
   99 |                         fr (cur, 0, 3) {
      |                         ^~

• Subtask 1: 0 / 29
• Subtask 2: 0 / 37
• Subtask 3: 0 / 34