Submission #884685

#TimeUsernameProblemLanguageResultExecution timeMemory
884685willychanMeetings 2 (JOI21_meetings2)C++17
100 / 100
275 ms42444 KiB
#include<bits/stdc++.h> using namespace std; typedef long long ll; //#include<bits/extc++.h> //__gnu_pbds const int N = 2e5+5; vector<int> side[N]; int sz[N]; int dep[N]; int P[N][20]; void dfs(int cur,int p){ sz[cur]=1; for(auto i : side[cur]){ if(i!=p){ dfs(i,cur); sz[cur]+=sz[i]; } } } void built(int cur,int p){ P[cur][0]=p; for(auto i : side[cur]) { if(i!=p){ dep[i] = dep[cur]+1; built(i,cur); } } } int n; int centroid(int cur,int p){ for(auto i : side[cur]){ if(i==p) continue; if(sz[i]>n/2) return centroid(i,cur); } return cur; } int dis(int a,int b){ if(dep[a]>dep[b]) swap(a,b); int oga = a; int ogb = b; if(dep[a]!=dep[b]){ for(int i=19;i>=0;i--){ if(dep[P[b][i]]>dep[a]) b = P[b][i]; } b = P[b][0]; } assert(dep[a]==dep[b]); int c = 0; if(a==b) c = a; else{ for(int i=19;i>=0;i--){ if(P[a][i]!=P[b][i]) { a = P[a][i]; b = P[b][i]; } } c = P[a][0]; } return dep[oga]+dep[ogb]-2*dep[c]+1; } int main(){ ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0); cin>>n; for(int i=0;i<n-1;i++){ int a,b;cin>>a>>b; side[a].push_back(b); side[b].push_back(a); } dfs(1,0); int cen = centroid(1,0); dfs(cen,0); vector<int> ord; for(int i=1;i<=n;i++) ord.push_back(i); sort(ord.begin(),ord.end(),[&](const int &a,const int &b){return sz[a]>sz[b];}); built(cen,0); P[cen][0]=cen; for(int j=1;j<20;j++){ for(int i=1;i<=n;i++) P[i][j] = P[P[i][j-1]][j-1]; } vector<int> ans(n+1,0); int dia = 1; int one = cen; int two = -1; int head = 1; for(int i=(n/2+1);i>=0;i--){ while(head<n && sz[ord[head]]>=i){ int a = ord[head]; if(two==-1){ two = a; dia = max(dia,dis(a,one)); }else{ int dis1 = dis(a,one); int dis2 = dis(a,two); if(dis1>dia){ two = a; dia= dis1; }else if(dis2>dia){ one = a; dia = dis2; } } head++; } ans[i] = dia; } for(int i=1;i<=n;i++){ if(i&1) cout<<1<<"\n"; else cout<<ans[i/2]<<"\n"; } return 0; }
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