Submission #910781

#	Time	Username	Problem	Language	Result	Execution time	Memory
910781		imarn	Making Friends on Joitter is Fun (JOI20_joitter2)	C++14	0 / 100	4 ms	14964 KiB

joitter2

#include<bits/stdc++.h>
#define ld long double
#define pii pair<long long,int>
#define pll pair<ll,ll>
#define all(x) x.begin(),x.end()
#define pb push_back
#define f first
#define s second
#define vi vector<ll>
#define vvi vector<vi>
#define vpii vector<pii>
#define ll long long
#define siz(x) (ll)x.size()
using namespace std;
const int N=1e5+5;
ll pr[N],sz[N];
ll ans=0;
set<int>g[N],rg[N],ch[N];
int get(int r){
    return pr[r]==r?r:pr[r]=get(pr[r]);
}vector<pii>mer;
void addedge(int a,int b){
    ch[b].insert(a);
    g[a].insert(b);rg[b].insert(a);
    if(g[b].count(a))mer.pb({a,b});
}
int gsz(int x){
    return ch[x].size()+g[x].size()+rg[x].size();
}
void uni(int a,int b){
    if(a==b)return;
    if(gsz(a)<gsz(b))swap(a,b);
    ans += siz(ch[a])*sz[b]+siz(ch[b])*sz[a];
    pr[b]=a;sz[a]+=sz[b];
    for(auto it : ch[b]){
        if(ch[a].count(it))ans-=sz[a];
    }g[b].erase(a);rg[b].erase(a);
    for(auto it : g[b]){
        addedge(a,it);
    }
    for(auto it : rg[b]){
        addedge(it,a);
    }
}
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n,m;cin>>n>>m;
    for(int i=1;i<=n;i++)pr[i]=i,sz[i]=1,ch[i].insert(i);
    while(m--){
        int a,b;cin>>a>>b;
        a=get(a),b=get(b);
        if(a==b||ch[b].count(a)){
            cout<<ans<<'\n';
            continue;
        }
        addedge(a,b);
        ans+=sz[b];
        while(!mer.empty()){
            uni(get(mer.back().f),get(mer.back().s));mer.pop_back();
        }cout<<ans<<'\n';
    }
}

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