Submission #1304251

#	Time	Username	Problem	Language	Result	Execution time	Memory
1304251		KietJ	Snake Escaping (JOI18_snake_escaping)	C++17	100 / 100	402 ms	30136 KiB

snake_escaping

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define f first
#define s second
#define sz(a) (int)((a).size())
#define all(a) (a).begin(), (a).end()
#define uni(a) sort(all(a)), (a).resize(unique(all(a)) - (a).begin())

typedef pair <int, int> ii;

const int N = 5e3 + 10;

int n, q, v[1 << 20];
string s;
ll f[1 << 20], g[1 << 20];

void solve() {
    cin >> n >> q >> s;
    for (int i = 0; i < (1 << n); i++) {
        v[i] = s[i] - '0';
        g[((1 << n) - 1) ^ i] = v[i];
        f[i] = v[i];
    }

    for (int i = 0; i < n; i++) {
        for (int mask = 0; mask < (1 << n); mask++) {
            if (mask & (1 << i)) {
                f[mask] += f[mask ^ (1 << i)];
                g[mask] += g[mask ^ (1 << i)];
            }
        }
    }

    while (q--) {
        cin >> s;
        int l = 0, r = n - 1;
        while (l <= r) {
            swap(s[l], s[r]);
            l++, r--;
        }

        int d0 = 0, d1 = 0, d2 = 0, x = 0, y = 0, z = 0;
        for (int i = 0; i < n; i++) {
            if (s[i] == '0') {
                x |= (1 << i);
                d0++;
            }

            if (s[i] == '1') {
                y |= (1 << i);
                d1++;
            }

            if (s[i] == '?') {
                z |= (1 << i);
                d2++;
            }
        }

        if (d2 <= 6) {
            ll ans = 0;
            for (int mask = z; ; mask = (mask - 1) & z) {
                ans += v[mask | y];

                if (mask == 0)
                    break;
            }
            cout << ans << '\n';
            continue;
        }

        if (d1 <= 6) {
            ll ans = 0;
            for (int mask = y; ; mask = (mask - 1) & y) {
                if (__builtin_popcount(mask ^ y) & 1) ans -= f[mask | z];
                else ans += f[mask | z];

                if (mask == 0)
                    break;
            }
            cout << ans << '\n';
            continue;
        }

        if (d0 <= 6) {
            ll ans = 0;
            for (int mask = x; ; mask = (mask - 1) & x) {
                if (__builtin_popcount(mask ^ x) & 1) ans -= g[mask | z];
                else ans += g[mask | z];

                if (mask == 0)
                    break;
            }
            cout << ans << '\n';
            continue;
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    // freopen("a.inp", "r", stdin);
    // freopen("a.out", "w", stdout);

    int t = 1;
    // cin >> t;

    while (t--) {
        solve();
    }

    return 0;
}
 

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 10 / 10
• Subtask 4: 53 / 53
• Subtask 5: 25 / 25