Submission #890221

#	Time	Username	Problem	Language	Result	Execution time	Memory
890221		avighna	Snake Escaping (JOI18_snake_escaping)	C++17	0 / 100	14 ms	65536 KiB

snake_escaping

#include <bits/stdc++.h>

using namespace std;

const int L = 20;

using Node = map<int, int>;

string s;
int l;

Node seg[1 << (L + 2)];

class Trie {
public:
  vector<Trie *> ptrs;
  void construct() { ptrs = vector<Trie *>(3, nullptr); }
  void add(int x, int l) {
    if (l == 0) {
      return;
    }
    int d = x % 3;
    if (ptrs[d] == nullptr) {
      ptrs[d] = (Trie *)calloc(sizeof(Trie), 1);
      ptrs[d]->construct();
    }
    ptrs[d]->add(x / 3, l - 1);
  }
  bool _exists(int x, int l) {
    if (l == 0) {
      return true;
    }
    int d = x % 3;
    if (ptrs[d] == nullptr) {
      return false;
    }
    return ptrs[d]->_exists(x / 3, l - 1);
  }
  bool exists(int x, int l) {
    string s;
    for (int i = 0; i < l; ++i) {
      s.push_back(x % 3 + '0');
      x /= 3;
    }
    for (int i = 0; i < l; ++i) {
      x = 3 * x + (s[i] - '0');
    }
    return _exists(x, l);
  }
};

Trie *trie;

void construct(int v, int tl, int tr, int d) {
  if (tl == tr) {
    seg[v][0] = s[tl] - '0';
    return;
  }

  int tm = (tl + tr) / 2;
  construct(2 * v, tl, tm, d + 1);
  construct(2 * v + 1, tm + 1, tr, d + 1);

  for (auto &i : seg[2 * v]) {
    if (trie->exists(3 * i.first, l - d)) {
      seg[v][3 * i.first] = i.second;
    }
    if (trie->exists(3 * i.first + 2, l - d)) {
      seg[v][3 * i.first + 2] = seg[2 * v][i.first] + seg[2 * v + 1][i.first];
    }
  }
  for (auto &i : seg[2 * v + 1]) {
    if (trie->exists(3 * i.first + 1, l - d)) {
      seg[v][3 * i.first + 1] = i.second;
    }
  }

  seg[2 * v].clear();
  seg[2 * v + 1].clear();
}

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

  int q;
  cin >> l >> q;
  cin >> s;

  vector<int> queries;
  trie = (Trie *)calloc(sizeof(Trie), 1);
  trie->construct();
  while (q--) {
    string sq;
    cin >> sq;
    int x = 0, y = 0;
    for (char &c : sq) {
      if (c == '?') {
        c = '2';
      }
    }
    for (int i = sq.length() - 1; i >= 0; --i) {
      x = 3 * x + (sq[i] - '0');
    }
    for (int i = 0; i < sq.length(); ++i) {
      y = 3 * y + (sq[i] - '0');
    }
    queries.push_back(x);
    trie->add(y, l);
  }

  construct(1, 0, (1 << l) - 1, 0);
  for (auto &i : queries) {
    cout << seg[1][i] << "\n";
  }
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:105:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |     for (int i = 0; i < sq.length(); ++i) {
      |                     ~~^~~~~~~~~~~~~

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