Submission #714111

#	Time	Username	Problem	Language	Result	Execution time	Memory
714111		becaido	Snake Escaping (JOI18_snake_escaping)	C++17	75 / 100	2090 ms	26256 KiB

snake_escaping

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;

#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof... (u) ? ", " : ""), dout (u...);}
#else
#define debug(...) 7122
#endif

#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second

const int SIZE = 20;
const int MAX = 1 << SIZE;

int n, m, q;
int a[MAX];
string s;
int dp0[MAX], dp1[MAX];

void solve() {
    cin >> n >> q;
    cin >> s;
    m = 1 << n;
    FOR (i, 0, m - 1) {
        a[i] = s[i] - '0';
        dp0[(m - 1) ^ i] = a[i];
        dp1[i] = a[i];
    }
    FOR (i, 0, n - 1) FOR (mask, 0, m - 1) if (mask >> i & 1) {
        dp0[mask] += dp0[mask ^ (1 << i)];
        dp1[mask] += dp1[mask ^ (1 << i)];
    }
    while (q--) {
        cin >> s;
        reverse(s.begin(), s.end());
        int cnt[3] = {};
        for (char c : s) (c == '0' ? cnt[0] : c == '1' ? cnt[1] : cnt[2])++;
        int p;
        FOR (i, 0, 2) if (cnt[i] == *min_element(cnt, cnt + 3)) {
            p = i;
            break;
        }
        int ans = 0;
        if (p == 2) {
            auto dfs = [&](auto dfs, int i, int mask)->void {
                if (i == n) {
                    ans += a[mask];
                    return;
                }
                if (s[i] == '0' || s[i] == '?') dfs(dfs, i + 1, mask);
                if (s[i] == '1' || s[i] == '?') dfs(dfs, i + 1, mask | (1 << i));
            };
            dfs(dfs, 0, 0);
        } else if (p == 0) {
            auto dfs = [&](auto dfs, int i, int mask, int cnt)->void {
                if (i == n) {
                    ans += (cnt & 1 ? -dp0[mask] : dp0[mask]);
                    return;
                }
                if (s[i] == '0') {
                    dfs(dfs, i + 1, mask | (1 << i), cnt - 1);
                    dfs(dfs, i + 1, mask, cnt);
                }
                if (s[i] == '1') dfs(dfs, i + 1, mask, cnt);
                if (s[i] == '?') dfs(dfs, i + 1, mask | (1 << i), cnt);
            };
            dfs(dfs, 0, 0, cnt[0]);
        } else {
            auto dfs = [&](auto dfs, int i, int mask, int cnt)->void {
                if (i == n) {
                    ans += (cnt & 1 ? -dp1[mask] : dp1[mask]);
                    return;
                }
                if (s[i] == '1') {
                    dfs(dfs, i + 1, mask | (1 << i), cnt - 1);
                    dfs(dfs, i + 1, mask, cnt);
                }
                if (s[i] == '0') dfs(dfs, i + 1, mask, cnt);
                if (s[i] == '?') dfs(dfs, i + 1, mask | (1 << i), cnt);
            };
            dfs(dfs, 0, 0, cnt[1]);
        }
        cout << ans << '\n';
    }
}

int main() {
    Waimai;
    solve();
}

Compilation message (stderr)

snake_escaping.cpp: In function 'void solve()':
snake_escaping.cpp:64:16: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
   64 |         } else if (p == 0) {
      |                ^~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 10 / 10
• Subtask 4: 53 / 53
• Subtask 5: 0 / 25