Submission #965420

#	Time	Username	Problem	Language	Result	Execution time	Memory
965420		four_specks	Snake Escaping (JOI18_snake_escaping)	C++17	100 / 100	551 ms	43460 KiB

snake_escaping

#include <bits/stdc++.h>

using namespace std;

namespace {}

void solve() {
  int h, q;
  cin >> h >> q;
  uint32_t n = 1 << h;
  string a;
  cin >> a;
  vector<int> b(n);
  for (uint32_t x = 0; x < n; x++) {
    b[x] = a[x] - '0';
  }
  vector dp_sub = b, dp_super = b;
  for (int s = 0; s < h; s++) {
    for (uint32_t x = n; x + 1 > 0; x--) {
      if (x >> s & 1) {
        dp_sub[x] += dp_sub[x ^ (1u << s)];
      }
    }
    for (uint32_t x = 0; x < n; x++) {
      if (!(x >> s & 1)) {
        dp_super[x] += dp_super[x | (1u << s)];
      }
    }
  }
  for (int i = 0; i < q; i++) {
    string t;
    cin >> t;
    reverse(t.begin(), t.end());
    array<uint32_t, 3> v;
    v.fill(0);
    for (int s = 0; s < h; s++) {
      if (t[s] == '0') {
        v[0] |= 1u << s;
      } else if (t[s] == '1') {
        v[1] |= 1u << s;
      } else {
        v[2] |= 1u << s;
      }
    }
    int ans = 0;
    {
      auto it = min_element(v.begin(), v.end(), [&](uint32_t x, uint32_t y) -> bool {
        return __builtin_popcount(x) < __builtin_popcount(y);
      });
      int p = distance(v.begin(), it);
      for (uint32_t x = v[p];; x = (x - 1) & v[p]) {
        if (p == 2) {
          ans += b[v[1] | x];
        } else {
          int term = p == 1 ? dp_sub[(v[1] ^ x) | v[2]] : dp_super[v[1] | x];
          if (__builtin_parity(x) == 0) {
            ans += term;
          } else {
            ans -= term;
          }
        }
        if (x == 0) {
          break;
        }
      }
    }
    cout << ans << '\n';
  }
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);

  solve();

  return 0;
}

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