Submission #957712

#	Time	Username	Problem	Language	Result	Execution time	Memory
957712		LCJLY	Meetings 2 (JOI21_meetings2)	C++14	100 / 100	812 ms	65600 KiB

meetings2

#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<long long,int>pii;
typedef pair<pii,pii>pi2;
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

vector<int>adj[200005];
int sz[200005];
int two[22][200005];
int d[200005];
int n;

void dfs(int index, int par){
	sz[index]=1;
	for(int x=0;x<20;x++){
		two[x+1][index]=two[x][two[x][index]];
	}
	for(auto it:adj[index]){
		if(it==par) continue;
		two[0][it]=index;
		d[it]=d[index]+1;
		dfs(it,index);
		sz[index]+=sz[it];
	}
}

int cent(int index, int par){
	for(auto it:adj[index]){
		if(it!=par&&sz[it]>n/2){
			return cent(it,index);
		}
	}
	return index;
}

int lca(int a, int b){
	if(d[a]>d[b]) swap(a,b);
	int diff=d[b]-d[a];
	for(int x=0;x<20;x++){
		if(diff&(1<<x)){
			b=two[x][b];
		}	
	}
	
	if(a==b) return a;
	for(int x=19;x>=0;x--){
		if(two[x][a]!=two[x][b]){
			a=two[x][a];
			b=two[x][b];
		}
	}
	return two[0][a];
}

int f(int a, int b){
	int hold=lca(a,b);
	return d[a]+d[b]-2*d[hold];
}

void solve(){
	cin >> n;
	
	int temp,temp2;
	for(int x=0;x<n-1;x++){
		cin >> temp >> temp2;
		adj[temp].push_back(temp2);
		adj[temp2].push_back(temp);
	}
	
	dfs(1,-1);
	int rt=cent(1,-1);
	memset(two,0,sizeof(two));
	dfs(rt,-1);
	//show(check,1);
	
	int ans[n+5];
	memset(ans,0,sizeof(ans));
	pii cur={rt,rt};
	int dist=0;
	
	vector<pii>v;
	for(int x=1;x<=n;x++){
		v.push_back({sz[x],x});
	}
	
	sort(v.begin(),v.end());
	reverse(v.begin(),v.end());
	
	for(int x=0;x<n;x++){
		int index=v[x].second;
		int hold=f(cur.first,index);
		int hold2=f(cur.second,index);
		pii temp={cur.second,index};
		if(hold>dist){
			cur={cur.first,index};
			dist=hold;
		}
		if(hold2>dist){
			dist=hold2;
			cur=temp;
		}
		
		ans[sz[index]]=dist;
	}
	
	for(int x=n;x>=0;x--){
		ans[x]=max(ans[x+1],ans[x]);
	}
	
	for(int x=1;x<=n;x++){
		if(x%2){
			cout << 1 << "\n";
		}
		else{
			cout << ans[x/2]+1 << "\n";
		}
	}
	
}
 
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int t=1;
	//cin >> t;
	while(t--){
		solve();
	}
}

• Subtask 1: 4 / 4
• Subtask 2: 16 / 16
• Subtask 3: 80 / 80