Submission #171985

#	Time	Username	Problem	Language	Result	Execution time	Memory
171985		AlexPop28	Matching (CEOI11_mat)	C++11	100 / 100	1002 ms	31964 KiB

mat

#include <bits/stdc++.h>
#define dbg() cerr <<
#define name(x) (#x) << ": " << (x) << ' ' <<

using namespace std;

const int INF = (int)2e9;

template<class T, class F = function<T(const T&, const T&)>>
struct Fenwick {
  int n;
  T def;
  F f;
  vector<T> tree;
  Fenwick(int n_, T def_, F f_) : n(n_), def(def_), f(f_), tree(n + 1, def) {}
  inline int lsb(int x) {
    return x & -x;
  }
  void Update(int pos, T val) {
    for (++pos; pos <= n; pos += lsb(pos)) {
      tree[pos] = f(tree[pos], val);  
    }
  }
  T Query(int pos) {
    T ret = def;
    for (++pos; pos; pos -= lsb(pos)) {
      ret = f(ret, tree[pos]);
    }
    return ret;
  }
};

void GetSmallBig(const vector<int> &p, vector<int> &small, vector<int> &big) {
  int n = p.size();
  Fenwick<pair<int, int>> mn(n, {-1, -1}, [](pair<int, int> a, pair<int, int> b) {
    return max(a, b);
  });
  Fenwick<pair<int, int>> mx(n, {INF, -1}, [](pair<int, int> a, pair<int, int> b) {
    return min(a, b);
  });
  for (int i = 0; i < n; ++i) {
    small[i] = mn.Query(p[i]).second;
    big[i] = mx.Query(n - p[i] - 1).second;
    mn.Update(p[i], make_pair(p[i], i));
    mx.Update(n - p[i] - 1, make_pair(p[i], i));
  }
}

bool Match(int k, int i, const vector<int> &p,
  const vector<int> &small, const vector<int> &big) {
  
  bool ret = true;
  ret &= big[k] == -1 || p[i] < p[i - k + big[k]];
  ret &= small[k] == -1 || p[i] > p[i - k + small[k]];
  return ret;
}

void GetPi(const vector<int> &p, vector<int> &pi,
  const vector<int> &small, const vector<int> &big) {

  pi[0] = 0;
  int k = 0;
  for (int i = 1; i < (int)p.size(); ++i) {
    while (k != 0 && !Match(k, i, p, small, big)) k = pi[k - 1];
    if (Match(k, i, p, small, big)) ++k;
    pi[i] = k;
  }
}

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

  int n, m; cin >> n >> m;
  vector<int> p(n);
  for (int i = 0; i < n; ++i) {
    int s; cin >> s; --s;
    p[s] = i;
  }

  vector<int> small(n, -1), big(n, -1), pi(n);
  GetSmallBig(p, small, big);
  GetPi(p, pi, small, big);

  vector<int> text(m);
  for (int i = 0; i < m; ++i) {
    cin >> text[i];
  }

  vector<int> ans;
  int k = 0;
  for (int i = 0; i < m; ++i) {
    while (k != 0 && !Match(k, i, text, small, big)) k = pi[k - 1];
    if (Match(k, i, text, small, big)) ++k;
    if (k == n) {
      ans.emplace_back(i - n + 1);
      k = pi[k - 1];
    }
  }

  cout << ans.size() << endl;
  for (int &x : ans) {
    cout << 1 + x << ' ';
  }
  cout << endl;
}

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 8 / 8
• Subtask 10: 10 / 10
• Subtask 11: 10 / 10