Submission #552109

#	Time	Username	Problem	Language	Result	Execution time	Memory
552109		errorgorn	Jail (JOI22_jail)	C++17	5 / 100	207 ms	49960 KiB

jail

// Super Idol的笑容
//    都没你的甜
//  八月正午的阳光
//    都没你耀眼
//  热爱105°C的你
// 滴滴清纯的蒸馏水

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

#define int long long
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << ": " << x << endl

#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

int n,q;
vector<int> al[120005];
ii arr[120005];

int d[120005];
int tkd[120005][19];

void dfs(int i,int p){
	for (auto it:al[i]){
		if (it==p) continue;
		
		d[it]=d[i]+1;
		int curr=tkd[it][0]=i;
		rep(x,0,19){
			if (curr==-1) continue;
			curr=tkd[it][x+1]=tkd[curr][x];
		}
		dfs(it,i);
	}
}

int mov(int i,int k){
	rep(x,0,19) if (k&(1<<x)) i=tkd[i][x];
	return i;
}

int lca(int i,int j){
	if (d[i]<d[j]) swap(i,j);
	i=mov(i,d[i]-d[j]);
	if (i==j) return i;
	
	rep(x,19,0) if (tkd[i][x]!=tkd[j][x]){
		i=tkd[i][x];
		j=tkd[j][x];
	}
	
	return tkd[i][0];
}

struct UFDS{
	int p[120005];
	
	void reset(int n){
		rep(x,1,n+1) p[x]=x;
	}
	
	int par(int i){
		if (p[i]==i) return i;
		else return p[i]=par(p[i]);
	}
	
	void unions(int i,int j){
		i=par(i),j=par(j);
		p[i]=j;
	}
} fwd,bwd;

vector<int> al2[120005];
bool vis[120005];
vector<int> topo;

void dfs_top(int i){
	vis[i]=true;
	for (auto it:al2[i]) if (!vis[it]) dfs_top(it);
	topo.pub(i);
}

int pos[120005];
bool good[120005];

signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	int TC;
	cin>>TC;
	while (TC--){
		cin>>n;
		
		rep(x,1,n+1) al[x].clear();
		
		int a,b;
		rep(x,1,n){
			cin>>a>>b;
			al[a].pub(b);
			al[b].pub(a);
		}
		
		rep(x,1,n+1) rep(y,0,19) tkd[x][y]=-1;
		dfs(1,-1);
		
		fwd.reset(n);
		bwd.reset(n);
		
		cin>>q;
		rep(x,0,q){
			cin>>a>>b;
			
			arr[x]={a,b};
			
			int g=lca(a,b);
			while (d[a]>d[g]){
				fwd.unions(a,tkd[a][0]);
				a=fwd.par(a);
			}
			while (b!=1 && d[b]>d[g]){
				bwd.unions(b,tkd[b][0]);
				b=bwd.par(b);
			}
		}
		
		bool ok=true;
		rep(x,1,n+1) al2[x].clear();
		rep(x,2,n+1){
			bool f=fwd.par(x)!=x;
			bool b=bwd.par(x)!=x;
			
			if (f && b) ok=false;
			if (f) al2[x].pub(tkd[x][0]);
			if (b) al2[tkd[x][0]].pub(x);
		}
		
		if (!ok){
			cout<<"No"<<endl;
			continue;
		}
		
		topo={-1};
		rep(x,1,n+1) vis[x]=false;
		rep(x,1,n+1) if (!vis[x]) dfs_top(x);
		
		//for (auto it:topo) cout<<it<<" "; cout<<endl;
		rep(x,1,n+1) pos[topo[x]]=x;
		
		rep(x,1,n+1) good[x]=true;
		rep(x,0,q) good[arr[x].se]=false;
		
		vector<int> idx;
		rep(x,0,q) idx.pub(x);
		sort(all(idx),[](int i,int j){
			return pos[arr[i].fi]>pos[arr[j].fi];
		});
		
		fwd.reset(n);
		rep(x,1,n+1) for (auto y:al[x]) if (good[x] && good[y]) fwd.unions(x,y);
		
		for (auto it:idx){
			int a=arr[it].fi,b=arr[it].se;
			//cout<<"debug: "<<a<<" "<<b<<endl;
			
			good[b]=true;
			for (auto it:al[b]) if (good[it]) fwd.unions(it,b);
			
			if (fwd.par(a)!=fwd.par(b)) ok=false;
		}
		
		if (ok) cout<<"Yes"<<endl;
		else cout<<"No"<<endl;
	}
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 16
• Subtask 4: 0 / 28
• Subtask 5: 0 / 12
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23