Submission #1127975

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127975		bunhadasou	Synchronization (JOI13_synchronization)	C++20	100 / 100	219 ms	21932 KiB

synchronization

#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define PB push_back
#define EB emplace_back
#define ll long long
#define bit(n,i) ((n>>i)&1)
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()
#define TASK "cf"
using namespace std;

struct fenwick{
    vector<int>ft;
    int lim;
    void reset(int _n){
        lim=_n+5;
        ft.assign(_n+10,0);
    }
    void upd(int pos,int val){
        for(;pos<=lim;pos+=pos&-pos) ft[pos]+=val;
    }
    int get(int pos){
        int res=0;
        for (;pos>0;pos-=pos&-pos) res+=ft[pos];
        return res;
    }
    void updating(int l,int r,int val){
        upd(l,val);upd(r+1,-val);
    }
};

const int LOG=17;
const int maxn=1e5+5;
const int max_edge=2e5+5;
vector<int>adj[maxn];
bool active[max_edge];
int in[maxn],out[maxn],par[maxn][LOG],val[maxn],last[maxn];
int time_dfs;
pair<int,int>edge[max_edge];
int n,m,q;
fenwick ft;


int get_anc(int u){
    int origin=u;
    for (int i=LOG-1;i>=0;i--) {
        if (par[u][i] &&ft.get(in[par[u][i]])==ft.get(in[origin])) u=par[u][i];
    }
    return u;
}

void dfs(int u,int p){
    in[u]=++time_dfs;
    for (auto v:adj[u]) {
        if (v==p) continue;
        par[v][0]=u;
        for (int i=1;i<LOG;i++) par[v][i]=par[par[v][i-1]][i-1];
        dfs(v,u);
    }
    out[u]=time_dfs;
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    // freopen(TASK".inp","r",stdin);
    // freopen(TASK".out","w",stdout);
    cin>>n>>m>>q;
    ft.reset(n);
    for (int i=1;i<n;i++){
        int u,v; cin>>u>>v;
        edge[i].fi=u;edge[i].se=v;
        adj[u].PB(v);adj[v].PB(u);
    }
    dfs(1,-1);
//    for (int i=1;i<=n;i++) cout<<in[i]<<" "<<out[i]<<"\n";
    for (int i=1;i<=n;i++) {
        ft.updating(in[i],out[i],-1);
        val[i]=1;
    }
    get_anc(1);
    for (int i=1;i<=m;i++) {
        int idx; cin>>idx;
        int u=edge[idx].fi,v=edge[idx].se;
        if (v==par[u][0]) swap(u,v);
        if (active[idx]){
//            cout<<get_anc(u)<<" "<<val[get_anc(u)]<<"\n";
            val[v]=last[v]=val[get_anc(u)];
            ft.updating(in[v],out[v],-1);
        }
        else {
            val[get_anc(u)]+=val[v]-last[v];
            ft.updating(in[v],out[v],1);
        }
        active[idx]=!active[idx];
    }
    while(q--){
        int u; cin>>u;
        cout<<val[get_anc(u)]<<"\n";
    }




    cerr<<"Time running "<<1000*clock()/CLOCKS_PER_SEC<<" ms\n";
    return 0;
}

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