1549C - Web of Lies - CodeForces Solution

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef unsigned long long ull;
#define fast ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ordered_set tree<pair<int, int>, null_type,less<pair<int,int>>, rb_tree_tag,tree_order_statistics_node_update>
#define all(v) (v).begin(),(v).end()
#define r_all(v) (v).rbegin(),(v).rend()
#define s(v) (v).size()
#define endl "\n";
#define NO cout << "NO\n";
#define YES cout << "YES\n";
#define No cout << "No\n";
#define Yes cout << "Yes\n";
#define PF push_front
#define PB push_back
#define MP make_pair
#define F first
#define S second

const int MOD = 1e9 + 7;
const int N = 1e6 + 5;

//_____________________________________________________Mostly_used______________________________________________________

void print_vec(vector<ll>& v){
    for(ll i=0; i<s(v); i++) cout << v[i] << " ";
    cout << endl
}
bool is_sorted(vector<ll>& v){
    bool x = true;
    for(ll i=0; i<s(v)-1; i++) x &= (v[i] <= v[i+1]);
    return x;
}
bool is_palindrome_s(string s) {
    string p = s;
    reverse(all(p));
    if (s == p) return true;
    else return false;
}
bool is_palindrome_n(ll n) {
    ll temp = n, sum =0 ,r;
    while(n>0)
    {
        r=n%10;
        sum = (sum*10)+r;
        n/=10;
    }
    if (temp == sum) return true;
    else return false;
}

//_____________________________________________________/Mostly_used_____________________________________________________



int main() {
    fast
    ll n, m; cin >> n >> m;
    ll ans = n;
    vector<ll> deg(n+1, 0);
    while(m--){
        ll u, v; cin >> u >> v;
        if(u < v) swap(u, v);
        if(!deg[v]) ans--;
        deg[v]++;
    }
    ll q; cin >> q;
    while(q--){
        ll type, u, v; cin >> type;
        if(type == 1){
            cin >> u >> v;
            if(u < v) swap(u, v);
            if(!deg[v]) ans--;
            deg[v]++;
        }
        else if(type == 2){
            cin >> u >> v;
            if(u < v) swap(u, v);
            deg[v]--;
            if(deg[v] == 0) ans++;
        }
        else if(type == 3){
            cout << ans << endl
        }
    }
    return 0;
}