Submission #1182716

#	Time	Username	Problem	Language	Result	Execution time	Memory
1182716		mertbbm	Making Friends on Joitter is Fun (JOI20_joitter2)	C++20	0 / 100	2 ms	4928 KiB

joitter2

#include <bits/stdc++.h>
using namespace std;

#define int long long 
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << "  " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << "  " << j << " " << #i << "  " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cout << it << " "; cout << #x << endl;
typedef pair<int,int>pii;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());

set<int>se[100005];

struct DSU{
	vector<int>e; 
	void init(int n){
		e=vector<int>(n,-1);
	}
	
	int get(int x){
		return e[x]<0?x:e[x]=get(e[x]);
	}
	
	bool unite(int x, int y){
		x=get(x); y=get(y);
		if(x==y) return 1;
		if(e[x]>e[y]) swap(x,y);
		if(se[x].size()<se[y].size()) swap(se[x],se[y]);
		for(auto it:se[y]) se[x].insert(it);
		e[x]+=e[y];
		e[y]=x;
		return 0;
	}
};

int f(int a){
	return a*(a-1);
}

void solve(){
	int n,m;
	cin >> n >> m;
	
	int a,b;
	int counter=0;
	DSU dsu;
	dsu.init(n+5);
	for(int x=0;x<m;x++){
		cin >> a >> b;
		int hold=dsu.get(b);
		int hold2=dsu.get(a);
		//cout << hold << " " << hold2 << "\n";
		if(hold==hold2){}
		else if(se[hold2].find(b)!=se[hold2].end()){
			//bidirectional
			
			counter-=(-dsu.e[hold])*(se[hold].size());
			counter-=(-dsu.e[hold2])*(se[hold2].size());
			counter-=f(-dsu.e[hold]);
			counter-=f(-dsu.e[hold2]);
			
			//cout << counter << " counter\n";
			
			dsu.unite(a,b);
			hold=dsu.get(a);
			
			if(se[hold].find(a)!=se[hold].end()) se[hold].erase(a);
			if(se[hold].find(b)!=se[hold].end()) se[hold].erase(b);
			
			counter+=f(-dsu.e[hold]);
			counter+=(-dsu.e[hold])*(se[hold].size());
		}
		else{
			if(se[hold].find(a)==se[hold].end()){
				se[hold].insert(a);
				counter+=-dsu.e[hold];
			}
		}
		cout << counter << "\n";
	}
}
																   
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int t=1;
	//cin >> t;
	while(t--){
		solve();
	}
}

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