Submission #895710

#	Time	Username	Problem	Language	Result	Execution time	Memory
895710		imarn	Synchronization (JOI13_synchronization)	C++14	100 / 100	207 ms	24148 KiB

synchronization

#include<bits/stdc++.h>
#define ld long double
#define pii pair<long long,int>
#define pll pair<ll,ll>
#define all(x) x.begin(),x.end()
#define pb push_back
#define f first
#define s second
#define vi vector<ll>
#define vvi vector<vi>
#define vpii vector<pii>
#define ll long long
using namespace std;
const int N=1e5+5;
vector<int>g[N];
vpii edge(N);
int fw[N]{0},pr[N][18]{0},tin[N],tout[N],t=0,d[N]{0},dd[N]{0};
bool vis[N]{0};
void add(int i,int amt){
    for(;i<N;i+=i&-i)fw[i]+=amt;
}
int qr(int i,int res=0){
    for(;i;i-=i&-i)res+=fw[i];
    return res;
}
int get(int u){
    int x=qr(tin[u]);
    for(int i=17;i>=0;i--)if(qr(tin[pr[u][i]])==x)u=pr[u][i];
    return u;
}
void dfs(int u,int p){
    pr[u][0]=p;tin[u]=++t;
    for(int i=1;i<=17;i++)pr[u][i]=pr[pr[u][i-1]][i-1];
    for(auto v:g[u]){
        if(v==p)continue;
        dfs(v,u);
    }tout[u]=t;
}
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n,m,q;cin>>n>>m>>q;
    for(int i=1;i<=n-1;i++){
        cin>>edge[i].f>>edge[i].s;
        g[edge[i].f].pb(edge[i].s);
        g[edge[i].s].pb(edge[i].f);
    }dfs(1,1);
    for(int i=1;i<=n;i++)add(tin[i],1),add(tout[i]+1,-1),d[i]=1;
    while(m--){
        int x;cin>>x;
        int u=edge[x].f,v=edge[x].s;
        if(v==pr[u][0])swap(u,v);
        if(!vis[x]){
            d[get(u)]+=d[v]-dd[v];vis[x]=1;
            add(tin[v],-1);add(tout[v]+1,1);
        }
        else {
            d[v]=dd[v]=d[get(u)];vis[x]=0;
            add(tin[v],1);add(tout[v]+1,-1);
        }
    }
    while(q--){
        int x;cin>>x;cout<<d[get(x)]<<"\n";
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 10 / 10
• Subtask 4: 20 / 20
• Subtask 5: 40 / 40