Submission #67519

#	Time	Username	Problem	Language	Result	Execution time	Memory
67519		reality	Synchronization (JOI13_synchronization)	C++17	100 / 100	1407 ms	96360 KiB

synchronization

#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define vii vector < pii >
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class P , class Q > ostream& operator<<(ostream& stream, pair < P , Q > v){ stream << "(" << v.fi << ',' << v.se << ")"; return stream;}
template < class T > ostream& operator<<(ostream& stream, const vector<T> v){ stream << "[ "; for (int i=0; i<(int)v.size(); i++) stream << v[i] << " "; stream << "]"; return stream;}
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
const int LG = 20;
const int N = 1e6;
int e[LG][N];
vi g[N];
int s[N];
int bg[N];
int ed[N];
int ans[N];
int lst[N];
int Time = 0;
void dfs(int node = 1,int prev = 1) {
    bg[node] = ++Time;
    e[0][node] = prev;
    for (auto it : g[node])
        if (it != prev)
            dfs(it,node);
    ed[node] = Time + 1;
}
int t[N];
int n;
void upd(int i,int h) {
    for (;i <= n;i += i&(-i))
        t[i] += h;
}
int que(int i) {
    int ans = 0;
    for (;i;i -= i&(-i))
        ans += t[i];
    return ans;
}
int get(int v) {
    const int G = que(bg[v]);
    for (int k = 19;k >= 0;--k)
        if (que(bg[e[k][v]]) == G)
            v = e[k][v];
    return v;
}
vii E;
int main(void) {
    int m,q;
    cin>>n>>m>>q;
    for (int i = 1;i < n;++i) {
        int u,v;
        cin>>u>>v;
        g[u].pb(v);
        g[v].pb(u);
        E.pb(mp(u,v));
    }
    dfs();
    for (int k = 1;k < LG;++k)
        for (int i = 1;i <= n;++i)
            e[k][i] = e[k - 1][e[k - 1][i]];
    for (int i = 0;i + 1 < n;++i)
        if (bg[E[i].fi] > bg[E[i].se])
            swap(E[i].fi,E[i].se);
    for (int i = 1;i <= n;++i)
        upd(bg[i],1),upd(ed[i],-1),ans[i] = 1;
    while (m --) {
        int tp;
        cin>>tp;
        --tp;
        int u = E[tp].fi;
        int v = E[tp].se;
        int g = get(u);
        if (lst[tp] == -1) {
            upd(bg[v],1);
            upd(ed[v],-1);
            lst[tp] = ans[v] = ans[g];
        } else {
            upd(bg[v],-1);
            upd(ed[v],1);
            ans[g] += ans[v] - lst[tp];
            lst[tp] = -1;
        }
    }
    while (q --) {
        int node;
        cin>>node;
        cout << ans[get(node)] << '\n';
    }
    return 0;
}

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