Submission #788618

#	Time	Username	Problem	Language	Result	Execution time	Memory
788618		WLZ	Match (CEOI16_match)	C++17	100 / 100	62 ms	36756 KiB

match

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

class trie {
  private:
    struct trie_node {
      trie_node *parent;
      vector<trie_node*> children;
      vector<int> val;
    } *cur;
    string s;
  public:
    trie() {
      cur = new trie_node{nullptr, vector<trie_node*>(26, nullptr), vector<int>(26, -1)};
      s = "";
    }

    void update(char c, int x) {
      cur->val[c - 'a'] = x;
    }

    int query(char c) {
      return cur->val[c - 'a'];
    }

    void go_up() {
      cur = cur->parent;
      s.pop_back();
    }

    void go_down(char c) {
      if (cur->children[c - 'a'] == nullptr) cur->children[c - 'a'] = new trie_node{cur, vector<trie_node*>(26, nullptr), vector<int>(26, -1)};
      cur = cur->children[c - 'a'];
      s.push_back(c);
    }

    const char current_char() {
      if (cur->parent == nullptr) return '$';
      return s.back();
    }
};

int n;
string s;
vector< vector<int> > prev_l;

string solve(int l, int r) {
  if (l > r) return "";
  if (l + 1 == r) return "()";
  return "(" + solve(l + 1, prev_l[r][s[l] - 'a'] - 1) + ")" + solve(prev_l[r][s[l] - 'a'] + 1, r);
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> s;
  int n = (int) s.length();
  trie mp;
  prev_l.assign(n, vector<int>(26, -1));
  for (int i = 0; i < n; i++) {
    if (mp.current_char() == s[i]) mp.go_up();
    else mp.go_down(s[i]);
    mp.update(s[i], i);
    for (int j = 0; j < 26; j++) prev_l[i][j] = mp.query(j + 'a');
  }
  if (mp.current_char() != '$') cout << -1 << '\n';
  else cout << solve(0, n - 1) << '\n';
  return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 27 / 27
• Subtask 3: 63 / 63