Submission #1064339

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064339		Malix	Valley (BOI19_valley)	C++14	23 / 100	263 ms	17172 KiB

valley

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef pair<int,int> pi;
typedef vector<pi> pii;
typedef tuple<int,int,int> tii;
typedef vector<ll> li;
typedef vector<li> lii;
 
#define REP(i,a,b) for(int i=a;i<b;i++)
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define LSOne(s) ((s)&(-s))
 
ll INF=1e18+10;
int inf=2e9+10;
ll M=1e9+7;

int n,m,q,e;
vector<vector<pair<int,ll>>> a;
pii rds;
vi sp,p,sa,se;
int sval=0,eval=0;

void dfs(int x){
    sa[x]=sval++;
    for(auto u:a[x]){
        if(sa[u.F]!=-1)continue;
        p[u.F]=x;
        dfs(u.F);
    }
    se[x]=eval++;
}

bool ances(int x,int y){
    if(sa[x]>=sa[y]&&se[x]<=se[y])return 1;
    return 0;
}

int main() {   
    cin>>n>>m>>q>>e;e--;
    a.resize(n);p.resize(n,-1);sa.resize(n,-1);se.resize(n,-1);
    REP(i,0,n-1){
        int x,y;ll z;
        cin>>x>>y>>z;
        x--;y--;
        rds.PB({x,y});
        a[x].PB({y,z});
        a[y].PB({x,z});
    }
    sp.resize(m);
    REP(i,0,m)cin>>sp[i];
    dfs(e);
    REP(i,0,n-1)if(sa[rds[i].F]<sa[rds[i].S])swap(rds[i].F,rds[i].S);
    while(q--){
        int x,y;cin>>x>>y;
        x--;y--;
        if(ances(y,rds[x].F))cout<<0<<"\n";
        else cout<<"escaped\n";
    }
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 27
• Subtask 3: 23 / 23
• Subtask 4: 0 / 41