Submission #604462

#	Time	Username	Problem	Language	Result	Execution time	Memory
604462		Aleee	Match (CEOI16_match)	C++14	10 / 100	2084 ms	3336 KiB

match

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

#define pb push_back
#define all(a) (a).begin(), (a).end()
#define endl '\n'
#define forn(i, l, n) for (int i = l; i < int(n); i++)

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int, int> pii;

const int INF = 1e9 + 7;
int op = 0, cl = 0;
string solve(string str, int pos, int test, string ans, stack<char> st, int o)
{
  if (pos >= str.length() && test == 0)
    return ans;
  if (pos >= str.length())
    return "";

  if (test < 0)
    return "";
  if (st.empty())
  {
    ans += "(";
    st.push(str[pos]);
    return solve(str, pos + 1, test + 1, ans, st, o + 1);
  }
  if (st.top() != str[pos])
  {
    ans += "(";
    st.push(str[pos]);
    return solve(str, pos + 1, test + 1, ans, st, o + 1);
  }
  else
  {
    string a = "";
    if (o < op / 2 || 1)
    {
      st.push(str[pos]);
      a = solve(str, pos + 1, test + 1, ans + "(", st, o + 1);
      st.pop();
    }
    st.pop();
    string b = solve(str, pos + 1, test - 1, ans + ")", st, o);
    if (a.size() || b.size())
    {
      if (a.size())
        return a;
      else
        return b;
    }
    else
      return "";
  }
}
int main() // Ale C.
{
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  // freopen("output.txt", "w", stdout);
  string str;
  cin >> str;
  for (char c : str)
  {
    if (c == '(')
      op++;
    else
      cl++;
  }
  if (op % 2 != 0 || cl % 2 != 0)
  {
    cout << -1;
    return 0;
  }
  string ans = solve(str, 0, 0, "", stack<char>(), 0);
  cout << (ans.length() ? ans : "-1");
  return 0;
}

Compilation message (stderr)

match.cpp: In function 'std::string solve(std::string, int, int, std::string, std::stack<char>, int)':
match.cpp:18:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |   if (pos >= str.length() && test == 0)
      |       ~~~~^~~~~~~~~~~~~~~
match.cpp:20:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |   if (pos >= str.length())
      |       ~~~~^~~~~~~~~~~~~~~

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