Submission #698520

#	Time	Username	Problem	Language	Result	Execution time	Memory
698520		dattranxxx	Match (CEOI16_match)	C++11	10 / 100	1 ms	340 KiB

match

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

const int N = 1e5 + 5;
char ans[N];
string s;
vector<int> idx[26];

int n;

void solve(int l, int r) {
  if (l > r) return;
  int c = s[l] - 'a';
  int m = upper_bound(idx[c].begin(), idx[c].end(), r) - idx[c].begin() - 1;
  
  if (m == -1 || idx[c][m] <= l) {
    cout << -1;
    exit(0);
  }
  m = idx[c][m];
  
  ans[l] = '(';
  ans[m] = ')';
  
  solve(l + 1, m - 1);
  solve(m + 1, r);
  
}

int main() {
  cin.tie(0)->sync_with_stdio(0); cout.tie(0);
  cin >> s; 
  n = s.size();
  s = ' ' + s;
  for (int i = 1; i <= n; ++i) {
    idx[s[i] - 'a'].emplace_back(i);
  }
  
  solve(1, n);
  
  for (int i = 1; i <= n; ++i) {
    cout << ans[i];
  }
  
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 27
• Subtask 3: 0 / 63