Два массива
include <bits/stdc++.h>
using namespace std; int main(){ int n, m; cin >> n; vector<int> v(n), ans; set<int> sets; for (int i = 0; i < n; i++) cin >> v[i]; cin >> m; for (int i = 0; i < m; i++) { int abf; cin >> abf; sets.insert(abf); }
for (int i = 0; i < n; i++)
if (sets.count(v[i]) == 0)
ans.push_back(v[i]);
cout << ans.size() << endl;
for (auto k : ans)
cout << k << " ";
cout << endl;
}
include<bits/stdc++.h>
using namespace std; int main(){ int n,m,i,t=0,l=0; vector<int> k; cin>>n; int a[n]; for(i=0; i<n; i++) cin>>a[i]; cin>>m; int b[m]; for(i=0; i<m; i++) cin>>b[i]; for(i=0; i<n; i++){ t=0; for(int j=0; j<m; j++){ if(a[i]==b[j]) t++;} if(t==0){ k.push_back(a[i]); l++;}} cout<<l<<endl; for(i=0; i<l; i++) cout<<k[i]<<" "; }
//100% (A+)
include<bits/stdc++.h>
using namespace std; int main() { int say=0,eded,b; vector <long long > v; cin>>b; for(say=0;b>say;say++){ cin>>eded; v.push_back(eded); } long long a,d; cin>>a; long long arr[a]; for(b=0;a>b;b++){ cin>>arr[b]; } for(eded=0;v.size()>eded;eded++){ for(b=0;a>b;b++){ if(v[eded]==arr[b]){ v.erase(v.begin()+b); } } } for(eded=0;v.size()>eded;eded++){ cout<<v[eded]<<" "; } }
include <bits/stdc++.h>
define ll long long
using namespace std;
int main() { int n, m, a[100], b[100]; cin >> n; for (int i = 0; i < n; i++) { cin >> a[i]; } vector <int> v, ans; set <int> st; cin >> m; for (int i = 0; i < m; i++) { cin >> b[i]; } for (int i = 0; i < n; i++) { v.push_back(a[i]); } for (int i = 0; i < m; i++) { st.insert(b[i]); } for (int i = 0; i < n; i++) { if (!st.count(v[i])) { ans.push_back(v[i]); } } cout << ans.size() << endl; for (auto &i : ans) { cout << i << " "; } }