백준 알고리즘 1269번 : 대칭 차집합

링크

https://www.acmicpc.net/problem/1269

Sol1) Set

#include <bits/stdc++.h>
#define X first
#define Y second
#define pb push_back
#define sz(a) int((a).size())
#define fastio ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
using namespace std;
using ll = long long;
using ull = unsigned long long;
using dbl = double;
using ldb = long double;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using wector = vector<vector<int>>;
using tiii = tuple<int,int,int>;

int main() {
	fastio;
  set<int> a,b;
  int n,k; cin >> n >> k;
  for(int i = 0; i < n; i++){
    int t; cin >> t; a.insert(t);
  }
  for(int i = 0; i < k; i++){
    int c; cin >> c; b.insert(c);
  }
  int ans = 0;
  for(auto i = a.begin(); i != a.end(); i++){
    if(b.find(*i) == b.end()) ans++;
  }
  for(auto i = b.begin(); i != b.end(); i++){
    if(a.find(*i) == a.end()) ans++;
  }
  cout << ans << "\n";
  return 0;
}