Submission #939320

#	Time	Username	Problem	Language	Result	Execution time	Memory
939320		WonderfulWhale	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	0 / 100	1 ms	4956 KiB

joitter2

#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 p[MAXN];
int sz[MAXN];
set<int> M[MAXN];
set<pii> S;

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

void Union(int a, int b) {
	p[Find(a)] = Find(b);
}

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

	int n, m;
	cin >> n >> m;
	iota(p, p+n+1, 0);
	for(int i=0;i<m;i++) {
		int a, b;
		cin >> a >> b;
		if(S.count({b, a})==0) {
			S.insert({a, b});
		} else {
			//cerr << "Merging\n";
			Union(a, b);		
			S.erase({b, a});
		}
		int ans = 0;
		for(int i=1;i<=n;i++) {
			sz[i] = 0;
			M[i].clear();
		}
		for(int i=1;i<=n;i++) {
			sz[Find(i)]++;
		}
		for(pii x:S) {
			M[Find(x.nd)].insert(x.st);
		}
		for(int i=1;i<=n;i++) {
			ans += sz[i]*(sz[i]-1);
			ans += sz[i]*sz(M[i]);
		}
		cout << ans << "\n";
	}
}

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