Submission #939500

#TimeUsernameProblemLanguageResultExecution timeMemory
939500WonderfulWhaleMaking Friends on Joitter is Fun (JOI20_joitter2)C++17
100 / 100
896 ms71452 KiB
#include<bits/stdc++.h>
using namespace std;

#define int int64_t
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()

const int MAXN = 100'009;

int cnt[MAXN];
int p[MAXN];
int sz[MAXN];
int sum[MAXN];
vector<int> V[MAXN];
set<int> In[MAXN];
set<int> in[MAXN];
set<int> out[MAXN];
int ans;

int Find(int x) {
	return x==p[x]?x:p[x]=Find(p[x]);
}

void Union(int a, int b) {
	a = Find(a);
	b = Find(b);
	if(a==b) return;
	ans -= sz[a]*sz(In[a]);
	ans -= sz[b]*sz(In[b]);
	ans -= sz[a]*(sz[a]-1);
	ans -= sz[b]*(sz[b]-1);
	vector<int> union_queue;
	if(sz(out[a])+sz(in[a])<sz(out[b])+sz(in[b])) swap(a, b);
	for(int x:out[b]) {
		if(x==a) continue;
		if(in[a].count(x)) {
			union_queue.pb(x);
		}
		out[a].insert(x);
		in[x].erase(b);
		in[x].insert(a);
	}
	for(int x:In[b]) {
		if(Find(x)!=a) {
			In[a].insert(x);
		}
	}
	In[b].clear();
	for(int x:V[b]) {
		In[a].erase(x);
		V[a].pb(x);
	}
	V[b].clear();
	out[b].clear();
	for(int x:in[b]) {
		if(x==a) continue;
		if(out[a].count(x)) {
			union_queue.pb(x);
		}
		in[a].insert(x);
		out[x].erase(b);
		out[x].insert(a);
	}
	in[b].clear();
	p[b] = a;
	sz[a] += sz[b];
	ans += sz[a]*(sz[a]-1);
	ans += sz[a]*sz(In[a]);
	for(int x:union_queue) {
		Union(a, x);
	}
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

	int n, m;
	cin >> n >> m;
	iota(p, p+n+1, 0);
	fill(sz, sz+n+1, 1);
	for(int i=1;i<=n;i++) {
		V[i].pb(i);
	}
	for(int i=0;i<m;i++) {
		int a, b;
		cin >> a >> b;
		int A = Find(a);
		int B = Find(b);
		if(A==B) goto skip;
		out[A].insert(B);
		if(in[A].count(B)) {
			Union(A, B);
		} else {
			ans -= sz[B]*sz(In[B]);
			in[B].insert(A);
			In[B].insert(a);
			ans += sz[B]*sz(In[B]);
		}
		skip:
		cout << ans << "\n";
	}
}
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