BOJ 14646 - 욱제는 결정장애야!! [C++]

문제

링크

풀이

#include <iostream>
#include <set>
using namespace std;
 
void solve(void) {
  int n; cin >> n;
 
  set<int> s;
  int ans = 0;
  for (int i=0; i<2*n; i++) {
    int x; cin >> x;
    if (s.count(x)) s.erase(x);
    else s.insert(x);
    ans = max(ans, (int)s.size());
  }
  cout << ans;
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  solve();
  return 0;
}