Submission #1219941

#	Time	Username	Problem	Language	Result	Execution time	Memory
1219941		goulthen	Nautilus (BOI19_nautilus)	C++20	100 / 100	180 ms	820 KiB

nautilus

//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T>
using Tree =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
#define int long long
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define rep(i, a, b) for (int i = a; i <= b; ++i)
#define per(i, b, a) for (int i = b; i >= a; --i)
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(), (v).end()
#define lsb(x) (x)&(-x)
 
void setIO(string name = "") {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(nullptr);
    if (!name.empty()) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
}
ll fexp(ll a, ll b, ll m) {
    if (b == 0) return 1LL;
    ll p = a;
    ll ans = 1;
 
    while (b > 0) {
        if (b % 2 != 0) ans = (ans*p)%m;
        p = (p*p)%m;
        b >>= 1;
    }
    return ans;
}
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
const int MAXN = 5e2+10;
const int INF = 1e18+5;
const int MOD = 1e9+7;
char a[MAXN][MAXN];
bitset<510> dp[2][MAXN], mask[MAXN];
int n,m,k;
string cm;
 
void solve() {
    cin >> n >> m >> k;
    rep(i,1,n) {
        string s;cin >> s;
        rep(j,1,m) {
            a[i][j] = s[j-1];
            
            if (a[i][j] == '.') dp[0][i][j] = 1, mask[i][j] = 1;;
        }
    }
    cin >> cm;
 
    rep(l,0,k-1) {
        rep(i,1,n) {
            dp[1][i].reset();
        }
        rep(i,1,n) {
            if (i < n && (cm[l] == 'N' || cm[l] == '?')) dp[1][i] = (dp[1][i] | dp[0][i+1]);
            if (i > 1 && (cm[l] == 'S' || cm[l] == '?')) dp[1][i] = (dp[1][i] | dp[0][i-1]);
            if (cm[l] == 'W' || cm[l] == '?') dp[1][i] = (dp[1][i] | (dp[0][i]>>1));
            if (cm[l] == 'E' || cm[l] == '?') dp[1][i] = (dp[1][i] | (dp[0][i]<<1));
            dp[1][i] = (dp[1][i]&mask[i]);
        }
        rep(i,1,n) {
            dp[0][i] = dp[1][i];
        }
    }
    int cnt = 0;
    rep(i,1,n) rep(j,1,m) if (a[i][j] == '.') cnt+=dp[0][i][j];
    cout << cnt << '\n';
}
 
int32_t main() {
    setIO();
    int tt = 1;
    //cin >> tt;
 
    while (tt-- > 0) solve();
    
}

Compilation message (stderr)

nautilus.cpp: In function 'void setIO(std::string)':
nautilus.cpp:28:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         freopen((name + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
nautilus.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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