Submission #1189415

#	Time	Username	Problem	Language	Result	Execution time	Memory
1189415		zNatsumi	Synchronization (JOI13_synchronization)	C++20	40 / 100	8092 ms	16076 KiB

synchronization

#include <bits/stdc++.h>

using namespace std;

using ii = pair<int, int>;
const int N = 2e5 + 5;

int n, m, q, in[N], out[N], timer, pa[N], res[N], pre[N];
bool status[N];
ii edge[N];
vector<int> ad[N];

void dfs(int u, int p){
  in[u] = ++timer;
  for(auto v : ad[u])
    if(v != p) dfs(v, u);
  out[u] = timer;
}

int root(int u){
  while(pa[u] != u) u = pa[u];
  return u;
}

int32_t main(){
  cin.tie(0)->sync_with_stdio(0);
//  #define task "test"
//  if(fopen(task ".inp", "r")){
//    freopen(task ".inp", "r", stdin);
//    freopen(task ".out", "w", stdout);
//  }
  cin >> n >> m >> q;
  for(int i = 1; i < n; i++){
    int u, v; cin >> u >> v;
    ad[u].push_back(v);
    ad[v].push_back(u);
    edge[i] = {u, v};
  }
  dfs(1, -1);
  for(int i = 1; i <= n; i++){
    pa[i] = i;
    res[i] = 1;
    auto &[u, v] = edge[i];
    if(in[u] > in[v]) swap(u, v);
  }

  while(m--){
    int e; cin >> e;
    auto [u, v] = edge[e];

    status[e] ^= 1;
    if(status[e]){
      pa[v] = u;
      u = root(u);
      res[u] += res[v] - pre[e];
    }else{
      pa[v] = v;
      u = root(u);
      res[v] = pre[e] = res[u];
    }
  }
  while(q--){
    int u; cin >> u;
    cout << res[root(u)] << "\n";
  }

  return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 10 / 10
• Subtask 4: 20 / 20
• Subtask 5: 0 / 40