Submission #379802

#	Time	Username	Problem	Language	Result	Execution time	Memory
379802		Jarif_Rahman	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	0 / 100	1 ms	364 KiB

joitter2

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
int ttt = 0;
queue <pair<int, int>> q;
map<pair<int, int>, ll> mp;
struct dsu{
    int n;
    vector<int> p;
    vector<ll> sz;
    vector<set<int>> aa, bb;
    vector<ll> cnt;
    ll ans;
    dsu(int nn){
        n = nn;
        ans = 0;
        sz.resize(n, 1);
        p.resize(n);
        aa.resize(n);
        bb.resize(n);
        cnt.resize(n, 0);
        for(int i = 0; i < n; i++) p[i] = i;
    }
    int get(int x){
        if(p[x] != x) p[x] = get(p[x]);
        return p[x];
    }
    void unite(int a, int b){
        ttt++;
        a = get(a), b  = get(b);
        if(a == b) return;
        if(sz[b] + aa[b].size() + bb[b].size() > sz[a] + aa[a].size() + bb[a].size()) swap(a, b);
        ans-=sz[a]*(sz[a]-1);
        ans-=sz[a]*bb[a].size();
        ans-=sz[b]*(sz[b]-1);
        ans-=sz[b]*bb[b].size();

        aa[a].erase(b);
        aa[b].erase(a);
        bb[a].erase(b);
        bb[b].erase(a);

        for(int x: aa[b]){
            mp[{b, x}]--;
            if(aa[a].find(x) == aa[a].end()) mp[{a, x}]++;
            bb[x].erase(b);
            bb[x].insert(a);
            aa[a].insert(x);
        }
        aa[b].clear();

        for(int x: bb[b]){
            mp[{x, b}]--;
            if(bb[a].find(x) == bb[a].end()) mp[{x, a}]++;
            aa[x].erase(b);
            aa[x].insert(a);
            bb[a].insert(x);
        }
        bb[b].clear();

        sz[a]+=sz[b];
        sz[b] = 0;
        p[b] = a;
        ans+=sz[a]*bb[a].size();
        ans+=sz[a]*(sz[a]-1);

        
    }
    void add_edge(int a, int b){
        a = get(a), b = get(b);
        if(a == b) return;
        if(aa[a].find(b) != aa[a].end()) return;
        aa[a].insert(b);
        bb[b].insert(a);
        ans+=sz[b];
        cnt[b]++;
        mp[{a, b}]++;
        if(aa[b].find(a) != aa[b].end()) unite(a, b);
    }
};
 
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m; cin >> n >> m;
    dsu ds(n);
    for(int i = 0; i < m; i++){
        int a, b; cin >> a >> b; a--, b--;
        ds.add_edge(a, b);
        cout << ds.ans << "\n";
    }
}

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