Submission #522852

#	Time	Username	Problem	Language	Result	Execution time	Memory
522852		nathanlee726	Meetings 2 (JOI21_meetings2)	C++14	100 / 100	361 ms	59436 KiB

meetings2

//#include<i_am_noob_orz>
#include<bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;
#define ll long long
#define int ll
#define ull unsigned long long
#define pii pair<int,int>
#define X first
#define Y second
#define mod ((ll)1e9+7)
#define pb push_back
#define mp make_pair
#define abs(x) ((x)>0?(x):(-(x)))
#define F(n) Fi(i,n)
#define Fi(i,n) Fl(i,0,n)
#define Fl(i,l,n) for(int i=l;i<n;i++)
#define memres(a) memset(a,0,sizeof(a))
#define all(a) a.begin(),a.end()
#define sz(a) ((int)a.size())
#define ceiling(a,b) (((a)+(b)-1)/(b))
#define endl '\n'
#define bit_count(x) __builtin_popcountll((x))
#define ykh mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define jimmy_is_kind false
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> rbtree;
 
//#define LOCAL
#ifdef LOCAL
#define bug(...) cerr<<"#"<<__LINE__<<' '<<#__VA_ARGS__<<"- ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T && x, S&&...y) {cerr<<x<<", "; _do(y...);}
#define IOS()
#else
#define IOS() ios_base::sync_with_stdio(0), cin.tie(0)
#define endl '\n'
#define bug(...)
#endif
 
int add(int a,int b){return(a+b>=mod?a+b-mod:a+b);}
int sub(int a,int b){return(a<b?a+mod-b:a-b);}
int po(int a,int b){
	if(b==0)return 1;
	if(b==1)return(a%mod);
	int tem=po(a,b/2);
	if(b&1)return(((tem*tem)%mod)*a)%mod;
	else return(tem*tem)%mod; 
}
int GCD(int a,int b){
	int x=0;
	int ra,rb;
	while(a&&b){
		if(((a&1)==0)&&((b&1)==0)){
			a>>=1,b>>=1,x++;
		}
		else if((a^b)&1){
			if(a&1)b>>=1;
			else a>>=1;
		}
		else{
			ra=abs(a-b),rb=min(a,b);
			a=ra,b=rb;
		}
	}
	return max(a,b)<<x;
}
int gcd(int a,int b){if(b==0)return a;return gcd(b,a%b);}

int n,cn,mn=1e9,si[200010],pa[200010][18],o[200010],dep[200010];
vector<int> g[200010];
vector<pii> v;

void dfs(int p,int f){
	si[p]=1;
	int mxs=0;
	for(int u:g[p]){
		if(u==f)continue;
		dfs(u,p);
		si[p]+=si[u];
		mxs=max(mxs,si[u]);
	}
	mxs=max(mxs,n-1-si[p]);
	bug(p,mxs);
	if(mxs<=mn)mn=mxs,cn=p;
}

void dfs1(int p,int f,int d){
	si[p]=1;
	pa[p][0]=f;
	dep[p]=d;
	for(int u:g[p]){
		if(u==f)continue;
		dfs1(u,p,d+1);
		si[p]+=si[u];
	}
}

int dis(int x,int y){
	if(x==y)return 0;
	if(dep[x]<dep[y])swap(x,y);
	int len=dep[x]-dep[y];
	for(int i=17;i>=0;i--)if(len&(1ll<<i))x=pa[x][i];
	if(x==y)return len;
	for(int i=17;i>=0;i--){
		if(pa[x][i]!=-1&&pa[x][i]!=pa[y][i])len+=(1ll<<(i+1)),x=pa[x][i],y=pa[y][i];
	}
	return len+2;
}

signed main(){
	IOS();
	cin>>n;
	F(n-1){
		int x,y;
		cin>>x>>y;
		--x,--y;
		g[x].pb(y);
		g[y].pb(x);
	}
	if(n==1){
		cout<<"1"<<endl;
		return 0;
	}
	dfs(0,-1);
	dfs1(cn,-1,0);
	bug(cn);
	Fi(j,17)F(n)pa[i][j+1]=(pa[i][j]==-1?-1:pa[pa[i][j]][j]);
	F(n){
		if(i!=cn)v.pb({si[i],i});
	}
	sort(all(v));
	pii dip={cn,cn};
	int di=0;
	for(int i=n-1;i>=0;i--){
		if(i%2==0){
			o[i]=1;
			continue;
		}
		int k=(i+1)/2;
		while(sz(v)&&v.back().X>=k){
			int t1,t2;
			t1=dis(v.back().Y,dip.X);
			t2=dis(v.back().Y,dip.Y);
			if(t1>t2){
				if(t1>di)dip={v.back().Y,dip.X},di=t1; 
			}
			else{
				if(t2>di)dip={v.back().Y,dip.Y},di=t2;
			}
			v.pop_back();
		}
		o[i]=di+1;
	}
	F(n)cout<<o[i]<<endl;
	return 0;
}
/*
14
8 13
13 10
13 7
6 8
5 7
10 4
9 5
12 8
6 2
4 11
5 1
9 3
4 14
*/

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