Submission #953259

#	Time	Username	Problem	Language	Result	Execution time	Memory
953259		andrei_boaca	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	17 / 100	5048 ms	69760 KiB

joitter2

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
ll n,m,ans;
ll comp[100005];
vector<ll> dsu[100005];
set<ll> par[100005];
set<pll> edgenod[100005];
set<ll> edgecomp[100005];
bool fst=1;
void dsu_merge(ll c1,ll c2)
{
    ll nr1=(int)dsu[c1].size()+(int)par[c1].size()+(int)edgenod[c1].size();
    ll nr2=(int)dsu[c2].size()+(int)par[c2].size()+(int)edgenod[c2].size();
    if(nr1<nr2)
        swap(c1,c2);
    ll sz2=dsu[c2].size();
    ll sz1=dsu[c1].size();
    ll val=(ll)dsu[c1].size()*(ll)dsu[c2].size();
    val=val*2LL;
    ans+=val;
    val=(ll)par[c1].size()*sz2;
    ans+=val;
    if(fst==1)
    {
        for(ll i:par[c1])
            if(edgecomp[comp[c1]].find(comp[i])!=edgecomp[comp[c1]].end())
                if(edgecomp[comp[i]].find(comp[c1])!=edgecomp[comp[i]].end())
                    assert(false);
    }
    set<ll> why;
    for(ll x:par[c2])
    {
        edgenod[comp[x]].erase({x,c2});
        if(edgecomp[comp[x]].find(c2)!=edgecomp[comp[x]].end())
            edgecomp[comp[x]].erase(c2);
        if(comp[x]==c1)
        {
            ans-=sz2;
            continue;
        }
        if(par[c1].find(x)==par[c1].end())
        {
            why.insert(comp[x]);
            par[c1].insert(x);
            ans+=sz1;
            edgenod[comp[x]].insert({x,c1});
            edgecomp[comp[x]].insert(c1);
        }
        else
            ans-=sz2;
    }
    for(pll p:edgenod[c2])
    {
        ll x=p.first;
        ll c=p.second;
        if(par[c].find(x)!=par[c].end())
            par[c].erase(x);
        if(c==c1)
        {
            ans-=(sz1+sz2);
            continue;
        }
        why.insert(comp[x]);
        edgenod[c1].insert({x,c});
        edgecomp[c1].insert(c);
        par[c].insert(x);
    }
    edgenod[c2].clear();
    par[c2].clear();
    edgecomp[c2].clear();
    for(ll i:dsu[c2])
    {
        dsu[c1].push_back(i);
        comp[i]=c1;
    }
    dsu[c2].clear();
    if(par[c1].empty())
        return;
    vector<pll> pls;
    bool found=0;
    if(fst==1)
    {
        for(ll i:why)
            if(edgecomp[comp[c1]].find(comp[i])!=edgecomp[comp[c1]].end())
                if(edgecomp[comp[i]].find(comp[c1])!=edgecomp[comp[i]].end())
                    found=1;
    }
    for(ll i:par[c1])
        if(edgecomp[comp[c1]].find(comp[i])!=edgecomp[comp[c1]].end())
            if(edgecomp[comp[i]].find(comp[c1])!=edgecomp[comp[i]].end())
            {
                /*if(fst==1)
                    assert(found);*/
                //dsu_merge(comp[i],comp[c1]);
                pls.push_back({comp[i],comp[c1]});
            }
    fst=0;
    for(pll p:pls)
    {
        ll a=p.first,b=p.second;
        if(comp[a]!=comp[b])
            dsu_merge(comp[a],comp[b]);
    }
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        comp[i]=i;
        dsu[i].push_back(i);
    }
    while(m--)
    {
        ll a,b;
        cin>>a>>b;
        ll c1=comp[a];
        ll c2=comp[b];
        if(c1==c2)
        {
            cout<<ans<<'\n';
            continue;
        }
        if(edgecomp[c2].find(c1)!=edgecomp[c2].end())
        {
            fst=1;
            dsu_merge(c1,c2);
            cout<<ans<<'\n';
            continue;
        }
        if(edgenod[c1].find({a,c2})==edgenod[c1].end())
        {
            ans+=dsu[c2].size();
            edgenod[c1].insert({a,c2});
            edgecomp[c1].insert(c2);
            par[c2].insert(a);
        }
        cout<<ans<<'\n';
    }
    return 0;
}

Compilation message (stderr)

joitter2.cpp: In function 'void dsu_merge(ll, ll)':
joitter2.cpp:83:10: warning: variable 'found' set but not used [-Wunused-but-set-variable]
   83 |     bool found=0;
      |          ^~~~~

• Subtask 1: 1 / 1
• Subtask 2: 16 / 16
• Subtask 3: 0 / 83