Submission #947858

#	Time	Username	Problem	Language	Result	Execution time	Memory
947858		willychan	Inside information (BOI21_servers)	C++17	2.50 / 100	185 ms	60856 KiB

servers

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
//#include<bits/extc++.h>
//__gnu_pbds


struct qT {
    int type;
    int a;
    int d;
    int t;
    qT(int _type,int _a,int _d,int _t):type(_type),a(_a),d(_d),t(_t) {}
};
const int N = 120005;
vector<pair<int,int> > side[N];
static const int B = 20;
int P[N][B];
pair<int,int> mx[N][B];
pair<int,int> mi[N][B];
pair<int,int> dfn[N];

struct Qstruct {
    int n;
    int T;
		
    void dfs(int cur,int p,int v) {
        dfn[cur].first=++T;
		P[cur][0]=p;
		mx[cur][0]={v,cur};
		mi[cur][0]={v,cur};
        for(auto e : side[cur]) {
            if(e.first!=p) dfs(e.first,cur,e.second);
        }
        dfn[cur].second=++T;
    }
	void init(int _n){
		T=0;	
		n=_n;
		dfs(1,1,0);
		for(int j=0;j<B;j++){
			P[1][j]=1;
			mx[1][j]={-1e9,1};
			mi[1][j]={1e9,1};
		}
		for(int j=1;j<B;j++){
			for(int i=2;i<=n;i++){
				P[i][j] = P[P[i][j-1]][j-1];
				mx[i][j] = max(mx[i][j-1],mx[P[i][j-1]][j-1]);
				mi[i][j] = min(mi[i][j-1],mi[P[i][j-1]][j-1]);
			}
		}
	}
	bool isanc(int a,int b){
		return ((dfn[a].first<=dfn[b].first)&&(dfn[a].second>=dfn[b].second));
	}
	int lca(int a,int b){
		if(isanc(a,b)) return a;
		if(isanc(b,a)) return b;
		for(int j=B-1;j>=0;j--){
			if(!isanc(P[b][j],a)) b = P[b][j];
		}
		return P[b][0];
	}
	pair<pair<int,int>,pair<int,int> > get(int a,int d){
		assert(isanc(a,d));
		assert(a!=d);
		pair<int,int> maxn = {-1e9,-1};
		pair<int,int> minn = {1e9,-1};
		for(int j=B-1;j>=0;j--){
			if(!isanc(P[d][j],a)){
				maxn = max(maxn,mx[d][j]);
				minn = min(minn,mi[d][j]);
				d = P[d][j];
				
			}
		}
		maxn = max(maxn,mx[d][0]);
		minn = min(minn,mi[d][0]);
		return {minn,maxn};
	}
	bool query(int a,int d,int t){
		if(a==d) return 1;
		if(isanc(a,d)){
			auto [minn,maxn]  = get(a,d);
			if((minn.second!=d || P[maxn.second][0]!=a)) return 0;
			if(maxn.first>t) return 0;
			return 1;
		}
		if(isanc(d,a)){
			auto [minn,maxn] = get(d,a);
			if(maxn.second!=a || P[minn.second][0]!=d) return 0;
			if(maxn.first>t) return 0;
			return 1;
		}
		int c = lca(a,d);
		auto [mina,maxa]  = get(c,a);
		auto [mind,maxd]  = get(c,d);
		if(mind.second!=d || P[maxd.second][0]!=c) return 0;
		if(maxa.second!=a || P[mina.second][0]!=c) return 0;
		if(max(maxa.first,maxd.first)>t) return 0;
		return maxd.first<mina.first;
	}
};



int main() {
    ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    int n,k;
    cin>>n>>k;
    vector<qT> query;
    for(int i=1; i<=n+k-1; i++) {
        char t;
        cin>>t;
        if(t=='S') {
            int a,b;
            cin>>a>>b;
            side[a].push_back({b,i});
            side[b].push_back({a,i});
        }
        if(t=='Q') {
            int a,d;
            cin>>a>>d;
            query.emplace_back(0,a,d,i);
        }
        if(t=='C') {
            int d;
            cin>>d;
            query.emplace_back(1,0,d,i);
        }
    }
    Qstruct Qans;
    Qans.init(n);
    for(auto cur : query)	{
        if(cur.type==0) {
            if(Qans.query(cur.a,cur.d,cur.t)){
				cout<<"yes\n";
			}else{
				cout<<"no\n";
			}
        } else {
            cout<<0<<"\n";
        }
    }
    return 0;
}

/*
6 3
S 1 2
S 1 3
S 3 4
Q 5 1
S 4 5
S 1 6
Q 5 1
Q 1 5
*/

• Subtask 1: 0 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 2.5 / 2.5
• Subtask 4: 0 / 2.5
• Subtask 5: 0 / 5
• Subtask 6: 0 / 5
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 0 / 17.5
• Subtask 12: 0 / 17.5