Submission #519809

#	Time	Username	Problem	Language	Result	Execution time	Memory
519809		new_acc	Capital City (JOI20_capital_city)	C++14	11 / 100	3097 ms	405484 KiB

capital_city

#include<bits/stdc++.h>
#define fi first
#define se second
#define rep(a, b) for(int a = 0; a < (b); a++)
using namespace std;
typedef long long ll;
typedef vector<ll> vi;
typedef vector<ll> vl;
const int N=2e5+10;
const int L=19;
const int M=4e6+N+10;
vi graf[N],r[N],graf2[M];
int t[N],gl[N],spojna[M],ile[M],pre[N],post[M],kon[M];
pair<int,int> jump[N][L+1];
int l=0,l2=0,n,k;
bitset<M>kan;
bitset<M>vis;
void add(int a,int b){
	graf2[a].push_back(b);
}
void dfs(int v,int o,int g){
	pre[v]=++l2;
	gl[v]=g;
	jump[v][0]={o,++l};
	add(l,t[o-1]);
	for(int j=1;j<=L;j++) jump[v][j].fi=jump[jump[v][j-1].fi][j-1].fi,jump[v][j].se=++l,add(l,jump[v][j-1].se),add(l,jump[jump[v][j-1].fi][j-1].se);
	for(auto u:graf[v]){
		if(u==o) continue;
		dfs(u,v,g+1);
	}
}
int lca(int a,int b){
	if(gl[a]<gl[b]) swap(a,b);
	for(int i=L;i>=0;i--) if(gl[jump[a][i].fi]>=gl[b]) a=jump[a][i].fi;
	if(a==b) return a;
	int res=0;
	for(int i=L;i>=0;i--){
		if(jump[a][i].fi==jump[b][i].fi) res=jump[a][i].fi;
		else a=jump[a][i].fi,b=jump[b][i].fi;
	}
	return res;
}
void dod(int a,int l,int x){
	for(int i=L;i>=0;i--) if(gl[jump[a][i].fi]>=gl[l]) add(x,jump[a][i].se),a=jump[a][i].fi;
}
void dfs2(int v){
	if(vis[v]) return;
	vis[v]=1;
	for(auto u:graf2[v]) dfs2(u);
	post[l2++]=v;
}
void dfs3(int v,int s){
	if(vis[v]) return;
	vis[v]=1;
	spojna[v]=s;
	if(v<=k-1) ile[s]++;
	for(auto u:graf2[v]) dfs3(u,s);
}
void odw(){
	rep(i,l+1) kon[i]=graf2[i].size();
	rep(i,l+1) {
		for(int j=kon[i]-1;j>=0;j--) graf2[graf2[i][j]].push_back(i),swap(graf2[i][j],graf2[i][graf2[i].size()-1]),graf2[i].pop_back();
		graf2[i].shrink_to_fit();
	}
}
void solve(){
	cin>>n>>k;
	rep(i,n-1){
		int a,b;
		cin>>a>>b;
		graf[a].push_back(b),graf[b].push_back(a);
	}
	l=k-1;
	rep(i,n){
		cin>>t[i];
		t[i]--;
		r[t[i]].push_back(i+1);
	}
	dfs(1,1,1);
	vector<pair<int,int> >vv;
	rep(i,k){	
		vv.clear();
		for(auto u:r[i]) vv.push_back({pre[u],u});
		sort(vv.begin(),vv.end());
		for(int j=1;j<vv.size();j++){
			int l=lca(vv[j].se,vv[j-1].se);
			dod(vv[j].se,l,i),dod(vv[j-1].se,l,i);
		}
	}
	l2=0;
	rep(i,l+1) dfs2(i);
	rep(i,l+1) vis[i]=0;
	odw();
	int curr=0;
	for(int i=l;i>=0;i--) if(!vis[post[i]]) dfs3(post[i],++curr);
	odw();
	rep(i,l+1){
		bool b=0;
		for(auto u:graf2[i]) if(spojna[i]!=spojna[u]) b=1;
		if(!kan[spojna[i]]) kan[spojna[i]]=b;
	}
	int res=INT_MAX;
	rep(i,l+1) if(!kan[spojna[i]]) res=min(res,ile[spojna[i]]);
	cout<<res-1<<"\n";
}
int main(){
	ios_base::sync_with_stdio(0),cin.tie(0);
	solve();
}

Compilation message (stderr)

capital_city.cpp: In function 'void solve()':
capital_city.cpp:85:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |   for(int j=1;j<vv.size();j++){
      |               ~^~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 10 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 59