Submission #897571

#	Time	Username	Problem	Language	Result	Execution time	Memory
897571		avighna	Snake Escaping (JOI18_snake_escaping)	C++17	100 / 100	1969 ms	45300 KiB

snake_escaping

#include <bits/stdc++.h>

using namespace std;

#define ll long long

const ll N = 20;

ll dp[1 << N], dp2[1 << N];
ll cnt[256];

void get_locs(string &t, vector<ll> &loc, ll &val, char ch, bool q) {
  for (ll i = 0; i < t.length(); ++i) {
    if (t[i] == ch) {
      loc.push_back(t.length() - i - 1);
    }
    val += (1 << (t.length() - i - 1)) * (t[i] == '1' || (q && t[i] == '?'));
  }
}

void populate(queue<pair<ll, ll>> &q, vector<ll> &loc, ll val, ll n) {
  q.push({val, -1});
  for (ll i = 0; i < n; ++i) {
    ll sz = q.size();
    while (sz--) {
      ll v = q.front().first;
      ll idx = q.front().second + 1;
      q.pop();
      q.push({v, idx});
      v ^= (1 << loc[idx]);
      q.push({v, idx});
    }
  }
}

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

  ll l, q;
  cin >> l >> q;
  string s;
  cin >> s;

  for (ll i = 0; i < s.length(); ++i) {
    dp[i] = dp2[i] = s[i] - '0';
  }
  for (ll i = 0; i < N; ++i) {
    for (ll mask = 0; mask < (1 << N); ++mask) {
      if (mask & (1 << i)) {
        dp[mask] += dp[mask ^ (1 << i)];
      } else {
        dp2[mask] += dp2[mask ^ (1 << i)];
      }
    }
  }

  while (q--) {
    string t;
    cin >> t;
    ll ans = 0;
    cnt['1'] = cnt['0'] = cnt['?'] = 0;
    for (auto &i : t) {
      cnt[i]++;
    }

    vector<ll> loc;
    queue<pair<ll, ll>> q;
    ll val = 0;

    if (cnt['?'] <= 6) {
      get_locs(t, loc, val, '?', false);
      populate(q, loc, val, cnt['?']);
      while (!q.empty()) {
        ll v = q.front().first;
        q.pop();
        ans += s[v] - '0';
      }
    } else if (cnt['1'] <= 6) {
      get_locs(t, loc, val, '1', true);
      populate(q, loc, val, cnt['1']);
      while (!q.empty()) {
        ll v = q.front().first;
        q.pop();
        ans +=
            dp[v] *
            ((__builtin_popcount(v) - cnt['?']) % 2 == cnt['1'] % 2 ? 1 : -1);
      }
    } else {
      get_locs(t, loc, val, '0', false);
      populate(q, loc, val, cnt['0']);
      while (!q.empty()) {
        ll v = q.front().first;
        q.pop();
        ans += dp2[v] * ((__builtin_popcount(v) - cnt['1']) % 2 == 0 ? 1 : -1);
      }
    }
    cout << ans << "\n";
  }
}

Compilation message (stderr)

snake_escaping.cpp: In function 'void get_locs(std::string&, std::vector<long long int>&, long long int&, char, bool)':
snake_escaping.cpp:13:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |   for (ll i = 0; i < t.length(); ++i) {
      |                  ~~^~~~~~~~~~~~
snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:45:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |   for (ll i = 0; i < s.length(); ++i) {
      |                  ~~^~~~~~~~~~~~
snake_escaping.cpp:64:11: warning: array subscript has type 'char' [-Wchar-subscripts]
   64 |       cnt[i]++;
      |           ^

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