Submission #289786

#	Time	Username	Problem	Language	Result	Execution time	Memory
289786		rama_pang	Snake Escaping (JOI18_snake_escaping)	C++14	100 / 100	1369 ms	50540 KiB

snake_escaping

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

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

  int L, Q;
  cin >> L >> Q;
  vector<vector<int>> A(2, vector<int>(1 << L));
  vector<vector<int>> dp(2, vector<int>(1 << L)); // Subset Sum
  for (int i = 0; i < (1 << L); i++) {
    char c;
    cin >> c;
    dp[0][i] = A[0][i] = dp[1][i ^ ((1 << L) - 1)] = A[1][i ^ ((1 << L) - 1)] = (c - '0');
  }
  for (int bit = 0; bit < 2; bit++) {
    for (int i = 0; i < L; i++) {
      for (int mask = 0; mask < (1 << L); mask++) {
        if (mask & (1 << i)) {
          dp[bit][mask] += dp[bit][mask ^ (1 << i)];
        }
      }
    }
  }
  for (int qi = 0; qi < Q; qi++) { // O(Q 2^(L/3))
    string s;
    cin >> s;
    reverse(begin(s), end(s));
    int mask0 = 0;
    int mask1 = 0;
    int maskq = 0;
    for (int i = 0; i < L; i++) {
      if (s[i] == '0') mask0 |= 1 << i;
      if (s[i] == '1') mask1 |= 1 << i;
      if (s[i] == '?') maskq |= 1 << i;
    }
    int ans = 0;
    if (min(__builtin_popcount(mask0), __builtin_popcount(mask1)) < __builtin_popcount(maskq)) {
      if (__builtin_popcount(mask0) < __builtin_popcount(mask1)) {
        for (int m = mask0; ; m = (m - 1) & mask0) {
          ans += dp[1][(mask0 | maskq) ^ m] * ((__builtin_popcount(m) & 1) ? -1 : 1);
          if (!m) {
            break;
          }
        }
      } else {
        for (int m = mask1; ; m = (m - 1) & mask1) {
          ans += dp[0][(mask1 | maskq) ^ m] * ((__builtin_popcount(m) & 1) ? -1 : 1);
          if (!m) {
            break;
          }
        }
      }
    } else {
      for (int m = maskq; ; m = (m - 1) & maskq) {
        ans += A[0][mask1 | m];
        if (!m) {
          break;
        }
      }
    }
    cout << ans << "\n";
  }
  return 0;
}

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