Submission #893663

#	Time	Username	Problem	Language	Result	Execution time	Memory
893663		8pete8	Meetings 2 (JOI21_meetings2)	C++17	100 / 100	393 ms	32520 KiB

meetings2

#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<unordered_map>
#include <queue>
#include<cstring>
#include<float.h>
#include<limits.h>
#include <cassert>
#include<cmath>
#include<set>
#include<algorithm>
#include <iomanip>
#include<numeric> //gcd(a,b)
#include<bitset>
using namespace std;
#define ll long long
#define f first
#define endl "\n"
#define s second
#define pii pair<int,int>
#define ppii pair<pii,int>
#define vi vector<int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F(n) for(int i=0;i<n;i++)
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#pragma GCC optimize ("03,unroll-loops")
#define int long long
using namespace std;
const int mod=998244353,mxn=2e5+5,lg=30,inf=1e9,minf=-1e9,Mxn=100000;
int n,sz[mxn+10],h[mxn+10],mx[mxn+10],ans[mxn+10];
pair<pii,pii> v[mxn+10];
vector<int>adj[mxn+10];
bitset<mxn+10>del;
void getsz(int cur,int p){
    sz[cur]=1;
    for(auto i:adj[cur]){
        if(i==p||del[i])continue;
        getsz(i,cur);
        sz[cur]+=sz[i];
    }
}
int getcen(int cur,int p,int need){
    for(auto i:adj[cur])if(!del[i]&&i!=p&&sz[i]*2>need)return getcen(i,cur,need);
    return cur;
}
int cnt=0;
void dfs(int cur,int p){
    sz[cur]=1;
    for(auto i:adj[cur]){
        if(i==p||del[i])continue;
        h[i]=h[cur]+1;
        dfs(i,cur);
        sz[cur]+=sz[i];
    }
    mx[sz[cur]]=max(mx[sz[cur]],h[cur]);
}
void solve(int root){
    if(del[root])assert(0);
    getsz(root,-1);
    int node=getcen(root,-1,sz[root]);
    h[node]=0;
    int sum=sz[root];
    cnt=0;
    for(auto i:adj[node]){
        if(del[i]){
            cnt++;
            continue;
        }
        h[i]=1;
        dfs(i,node);
        mx[sz[i]+1]=minf;
        for(int j=sz[i];j>=0;j--){
            mx[j]=max(mx[j],mx[j+1]);
            if(mx[j]==minf)continue;
            if(v[j].f.f==-1||v[j].f.f<mx[j]){
                swap(v[j].f,v[j].s);
                v[j].f={mx[j],cnt};
            }
            else if(v[j].s.f==-1||v[j].s.f<mx[j])v[j].s={mx[j],cnt};
        }
        for(int j=0;j<=sz[i];j++)mx[j]=minf;
        cnt++;
    }
    int cmx=minf;
    for(int i=sum;i>=0;i--){
        if(v[i].f.f==-1)continue;
        if(v[i].f.s<0)assert(0);
        if(v[i].s.f==-1&&sum-sz[adj[node][v[i].f.s]]>=i)cmx=max(cmx,v[i].f.f);
        else if(v[i].s.f!=-1) cmx=max(cmx,v[i].f.f+v[i].s.f);
        ans[i]=max(ans[i],cmx);
        v[i]={{-1,-1},{-1,-1}};
    }
    del[node]=true;
    for(auto i:adj[node])if(!del[i])solve(i);
}
int32_t main(){
    cin>>n;
    for(int i=0;i<n-1;i++){
        int u,v;cin>>u>>v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    for(int i=0;i<=n;i++)v[i]={{-1,-1},{-1,-1}};
    fill(mx,mx+mxn+5,minf);
    solve(1);
    for(int i=1;i<=n;i++){
        if(i&1)cout<<1<<'\n';
        else cout<<ans[i/2]+1<<'\n';
    }
}

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