Submission #136394

#	Time	Username	Problem	Language	Result	Execution time	Memory
136394		popovicirobert	Nautilus (BOI19_nautilus)	C++14	100 / 100	72 ms	760 KiB

nautilus

#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast")
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
// 217
// 44


/*const int MOD = (int) 1e9 + 7;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}

inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}*/

/*int fact[], invfact[];

inline void prec(int n) {
    fact[0] = 1;
    for(int i = 1; i <= n; i++) {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    invfact[n] = lgput(fact[n], MOD - 2);
    for(int i = n - 1; i >= 0; i--) {
        invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
    }
}

inline int comb(int n, int k) {
    if(n < k) return 0;
    return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}*/

using namespace std;

const int MAXN = 500;

bitset <500> dp[2][MAXN], mat[MAXN];

int main() {
    //ifstream cin("A.in");
    //ofstream cout("A.out");
    int i, j, n, m, k;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n >> m >> k;

    for(i = 0; i < n; i++) {
        string str;
        cin >> str;

        for(j = 0; j < m; j++) {
            mat[i][j] = (str[j] == '.');
        }
        dp[0][i] = mat[i];
    }

    for(int t = 1; t <= k; t++) {
        char ch;
        cin >> ch;

        for(i = 0; i < n; i++) {
            dp[t & 1][i].reset();
        }

        if(ch == 'N' || ch == '?') {
            for(i = 0; i < n - 1; i++) {
                dp[t & 1][i] |= dp[1 - t & 1][i + 1];
            }
        }

        if(ch == 'W' || ch == '?') {
            for(i = 0; i < n; i++) {
                dp[t & 1][i] |= (dp[1 - t & 1][i] >> 1);
            }
        }

        if(ch == 'S' || ch == '?') {
            for(i = 1; i < n; i++) {
                dp[t & 1][i] |= dp[1 - t & 1][i - 1];
            }
        }

        if(ch == 'E' || ch == '?') {
            for(i = 0; i < n; i++) {
                dp[t & 1][i] |= (dp[1 - t & 1][i] << 1);
            }
        }

        for(i = 0; i < n; i++) {
            dp[t & 1][i] &= mat[i];
        }
    }

    int ans = 0;
    for(i = 0; i < n; i++) {
        for(j = 0; j < m; j++) {
            ans += dp[k & 1][i][j];
        }
    }

    cout << ans;

    return 0;
}

Compilation message (stderr)

nautilus.cpp: In function 'int main()':
nautilus.cpp:94:38: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
                 dp[t & 1][i] |= dp[1 - t & 1][i + 1];
                                    ~~^~~
nautilus.cpp:100:39: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
                 dp[t & 1][i] |= (dp[1 - t & 1][i] >> 1);
                                     ~~^~~
nautilus.cpp:106:38: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
                 dp[t & 1][i] |= dp[1 - t & 1][i - 1];
                                    ~~^~~
nautilus.cpp:112:39: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
                 dp[t & 1][i] |= (dp[1 - t & 1][i] << 1);
                                     ~~^~~

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