Submission #513907

#TimeUsernameProblemLanguageResultExecution timeMemory
513907EyedMaking Friends on Joitter is Fun (JOI20_joitter2)C++17
100 / 100
1347 ms69956 KiB
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cmath>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pii;
const ll MOD = 1e9 + 7;

//Making Friends on Joitter is Fun: JOI 2020/2
//Problem: https://oj.uz/problem/view/JOI20_joitter2

ll n, m;
//set<ll> conTo[100005]; //ConTo[a] contains things that connect to group a
set<ll> conU[100005]; //conU[a] contains a cup conTo[a]
set<ll> tGraph[100005]; // graph of arrows from pA to pB
set<ll> bGraph[100005];
ll cSize[100005];
ll up[100005];
ll sumT[100005]; //sumT[a] = sum of cSize[x] for x in conTo[a] 
ll curAns;
queue<pii> merg;

void goIn(ll a, ll b) {
	tGraph[a].insert(b);
	bGraph[b].insert(a);
	if (tGraph[b].find(a) != tGraph[b].end()) merg.push({ a,b });
}

ll par(ll b) {
	return (b == up[b] ? b : (up[b] = par(up[b])));
}

void con(ll a, ll b) {//connects a to b
	if (a == b) return;
	curAns += conU[a].size() * cSize[b];
	curAns += conU[b].size() * cSize[a];
	if (conU[a].size() < conU[b].size()) swap(a, b);
	for (auto itr = conU[b].begin(); itr != conU[b].end(); ++itr) {
		if (conU[a].find(*itr) != conU[a].end()) curAns -= (cSize[a] + cSize[b]);
	}
	for (auto itr = conU[b].begin(); itr != conU[b].end(); ++itr) {
		conU[a].insert(*itr);
	}
	up[b] = a;
	cSize[a] += cSize[b];

	tGraph[a].erase(b);
	tGraph[b].erase(a);
	bGraph[a].erase(b);
	bGraph[b].erase(a);
	for (ll i : tGraph[b]) {
		bGraph[i].erase(b);
		goIn(a, i);
	}
	for (ll i : bGraph[b]) {
		tGraph[i].erase(b);
		goIn(i, a);
	}

}
void init() {
	for (ll i = 1; i <= n; ++i) {
		cSize[i] = 1;
		up[i] = i;
		conU[i].insert(i);
	}
	curAns = 0;
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	cin >> n >> m;
	init();
	for (ll i = 0; i < m; ++i) {
		ll a, b;
		cin >> a >> b;
		b = par(b);
		if (par(a) != b && conU[b].find(a) == conU[b].end()) {
			conU[b].insert(a);
			curAns += cSize[b];
			a = par(a);
			goIn(a, b);
			while (!merg.empty()) {
				pii p = merg.front();
				merg.pop();
				con(par(p.first), par(p.second));
			}
		}
		cout << curAns << endl;
	}
	return 0;
}
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