Submission #418438

#	Time	Username	Problem	Language	Result	Execution time	Memory
418438		ngpin04	Making Friends on Joitter is Fun (JOI20_joitter2)	C++14	0 / 100	7 ms	11980 KiB

joitter2

#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
using namespace std;
const int N = 1e5 + 5; 
const int T = 1000;

multiset <int> in[N], out[N];

vector <int> node[N];

long long ans;

int par[N];
int n,m;

int getpar(int u) {
	return (par[u] < 0) ? u : (par[u] = getpar(par[u]));
}

void join(int u, int v) {
	u = getpar(u);
	v = getpar(v);
	if (u == v)
		return;
	if (in[u].size() + out[u].size() + node[u].size() < in[v].size() + out[v].size() + node[v].size())
		swap(u, v);
	ans += 2LL * par[u] * par[v];
	out[u].erase(v);
	for  (int x : node[v]) {
		if (in[u].count(x)) {
			in[u].erase(x);
			ans -= (-par[u]);
		}
		node[u].push_back(x);
	}

	ans += (long long) in[u].size() * (-par[v]);

	vector <int> add;

	for (int x : in[v]) {
		if (getpar(x) == u) 
			ans -= (-par[v]);
		else if (!in[u].count(x)) {
			out[x].erase(out[x].find(v));
			out[x].insert(u);
			in[u].insert(x);
			ans += (-par[u]);
			if (out[u].count(getpar(x)))
				add.push_back(getpar(x));
		}	
	}

	for (int x : out[v]) if (x != u) {
		out[u].insert(x);
		if (out[x].count(u))
			add.push_back(x);
	}

	par[u] += par[v];
	par[v] = u;

	for (int x : add)
		join(u, x);
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> m;
	for (int i = 1; i <= n; i++) {
		node[i].push_back(i);
		par[i] = -1;
	}

	for (int i = 1; i <= m; i++) {
		int u,v;
		cin >> u >> v;
		int pu = getpar(u);
		int pv = getpar(v);
		if (!in[pv].count(u)) {
			in[pv].insert(u);
			out[pu].insert(pv);
			ans += -par[pv];
			if (out[pv].count(pu))
				join(pu, pv);
		}
		cout << ans << "\n";
	}
	return 0;
}

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