Submission #694048

#	Time	Username	Problem	Language	Result	Execution time	Memory
694048		Shin	Snake Escaping (JOI18_snake_escaping)	C++14	100 / 100	1136 ms	39104 KiB

snake_escaping

#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair

using namespace std;
template <class X, class Y> bool minimize(X &a, Y b) {
    if (a > b) return a = b, true;
    return false;
}
template <class X, class Y> bool maximize(X &a, Y b) {
    if (a < b) return a = b, true;
    return false;
}

int lower[1 << 20];
int upper[1 << 20];
char a[1 << 20];

signed main() {
  cin.tie(0)->sync_with_stdio(0);
  int n, q; cin >> n >> q;
  for (int i = 0; i < 1 << n; i ++) {
    cin >> a[i];
  }
  for (int i = 0; i < 1 << n; i ++) {
    lower[i] = upper[i] = a[i] - '0';
  }
  for (int i = 0; i < n; i ++) {
    for (int mask = 0; mask < 1 << n; mask ++) {
      if (mask >> i & 1) {
        lower[mask] += lower[mask ^ (1 << i)];
      }
    }
  }
  for (int i = 0; i < n; i ++) {
    for (int mask = (1 << n) - 1; ~mask; mask --) {
      if (~mask >> i & 1) {
        upper[mask] += upper[mask ^ (1 << i)];
      }
    }
  }
  while (q --) {
    string s; cin >> s;
    reverse(s.begin(), s.end());
    int mask_a = 0, mask_b = 0, mask_c = 0;
    for (int i = 0; i < n; i ++) {
      if (s[i] == '0') {
        mask_a |= 1 << i;
      } 
      if (s[i] == '1') {
        mask_b |= 1 << i;
      }
      if (s[i] == '?') {
        mask_c |= 1 << i;
      }
    }
    int res = 0;
    if (__builtin_popcount(mask_c) <= 6) {
      for (int mask = mask_c; ~mask; mask = (mask - 1) & mask_c) {
        res += a[mask_b | mask] - '0';
        if (mask == 0) {
          break;
        }
      }
    } else
    if (__builtin_popcount(mask_a) <= 6) {
      for (int mask = mask_a; ~mask; mask = (mask - 1) & mask_a) {
        int cnt = __builtin_popcount(mask);
        res += ((cnt & 1) ? -1 : 1) * upper[mask | mask_b];
        if (mask == 0) {
          break;
        }
      }
    } else {
      for (int mask = mask_b; ~mask; mask = (mask - 1) & mask_b) {
        int cnt = __builtin_popcount(mask);
        res += ((cnt & 1) == (__builtin_popcount(mask_b) & 1) ? 1 : -1) * lower[mask | mask_c];
        if (mask == 0) {
          break;
        }
      }
    }
    cout << res << '\n';
  }
  return 0;
}

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