Submission #1108908

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108908		vjudge1	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	100 / 100	975 ms	115640 KiB

joitter2

#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)

#define int long long
typedef long long ll;
typedef pair<int,int> pii;

const ll maxn=3e5+10;
const ll offset=2e5;
const ll inf=1e18;
const int base=350;
const ll mod=998244353;
int n,m;
int par[maxn];
set<int> adj[maxn],adj_r[maxn],L[maxn];
int res;
vector<pii> Q;
int Find(int u)
{
    return par[u]<0?u:par[u]=Find(par[u]);
}

void Union(int u,int v)
{
    if ((u=Find(u))==(v=Find(v))) return;
    if (L[u].size() + adj[u].size() + adj_r[u].size() < L[v].size()+adj[v].size()+adj_r[v].size()) swap(u,v);
    res+=-par[u]*L[v].size() - par[v]*L[u].size();
//    cerr<<u<<' '<<v<<' '<< res<<'\n';
    par[u]+=par[v];
    par[v]=u;
    for(int x: L[v])
    {
        if (L[u].find(x)!=L[u].end())
        {
            res+=par[u];
            continue;
        }
        L[u].insert(x);
    }
    L[v].clear();
    adj[u].erase(v);adj_r[u].erase(v);adj[v].erase(u);adj_r[v].erase(u);
    for(int x:adj[v])
    {
//        x=Find(x);
        adj[u].insert(x);
        adj_r[x].insert(u);
        if (adj_r[u].find(x)!=adj_r[u].end()) Q.pb({u,x});
    }
//    adj[v].clear();
    for(int x:adj_r[v])
    {
//        x=Find(x);
        adj_r[u].insert(x);
        adj[x].insert(u);
//        cerr<< adj[u].count(x)<<'\n';
        if (adj[u].find(x)!=adj[u].end()) Q.pb({u,x});
    }
//    adj_r[v].clear();

}

void sol()
{
    cin >>n>>m;
    for1(i,1,n)
    {
        par[i]=-1;
        L[i].insert(i);
    }

    for1(i,1,m)
    {
        int u,v;cin >> u>> v;
        v=Find(v);
        if (u==v || L[v].find(u)!=L[v].end()) cout << res<<'\n';
        else
        {
            L[v].insert(u);
            u=Find(u);
            adj[u].insert(v);
            adj_r[v].insert(u);
            res-=par[v];
//            cerr<< res<<" ashiba\n";
            if (adj_r[u].find(v)!=adj_r[u].end()) Q.pb({u,v});
            while (!Q.empty())
            {
//                cerr<<" ulion "<<Q.back().fi<<' '<<Q.back().se<<'\n';
                pii x=Q.back();
                Q.pop_back();
                Union(x.fi,x.se);

            }
            cout << res<<'\n';

        }
    }

}
int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
//    freopen("adfaf.inp","r",stdin);
//    freopen("adfaf.out","w",stdout);

    int t=1;//cin >> t;
    while (t--) {
        sol();
    }
}

/*
4 3
1 2
2 3
3 2



*/

• Subtask 1: 1 / 1
• Subtask 2: 16 / 16
• Subtask 3: 83 / 83