Submission #873591

#	Time	Username	Problem	Language	Result	Execution time	Memory
873591		epicci23	Birthday gift (IZhO18_treearray)	C++17	56 / 100	1012 ms	95280 KiB

treearray

#include "bits/stdc++.h"
using namespace std;
#define int long long
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()
#define endl "\n"
#define pb push_back

/*
 dont get stuck on one approach
 write stuff on paper
 edge cases(n=1?)
 look for : dp,bs,bf,observations...
 implement and debug smarter
*/


const int N = 2e5 + 25;
const int LOG = 25;

vector<int> v[N];
int lift[N][LOG];
int depth[N];
void dfs(int c,int p,int d){
  depth[c]=d;
  lift[c][0]=p;
  for(int i=1;i<LOG;i++) lift[c][i]=lift[lift[c][i-1]][i-1];
  for(int x:v[c]){
  	if(x==p) continue;
    dfs(x,c,d+1);
  }
}

int lca(int a,int b){
  if(depth[a]<depth[b]) swap(a,b);
  int x = depth[a] - depth[b];
 
  for(int i=0;i<LOG;i++) if(x&(1LL<<i)) a=lift[a][i];
  
  if(a==b) return a;

  for(int i=LOG-1;i>=0;i--){
  	if(lift[a][i]!=lift[b][i]){
  	  a=lift[a][i];
  	  b=lift[b][i];
  	}
  }
  return lift[a][0];
}

void solve(){

  int n,m,q;
  cin >> n >> m >> q;
 
  for(int i=1;i<n;i++){
  	int a,b;
  	cin >> a >> b;
  	v[a].pb(b);
  	v[b].pb(a);
  }

  dfs(1,1,0);
  
  int ar[m+5];
  set<int> s[n+5];
  set<int> freq[n+5];

  for(int i=1;i<=m;i++){
    cin >> ar[i];
    if(i>1) s[lca(ar[i],ar[i-1])].insert(i);
    freq[ar[i]].insert(i);
  } 
 
  while(q--){

    int op;
    cin >> op;

    if(op==1){
      int ind,u;
      cin >> ind >> u;
      
      if(ind>1) s[lca(ar[ind],ar[ind-1])].erase(ind);
      if(ind<n) s[lca(ar[ind],ar[ind+1])].erase(ind+1);
      freq[ar[ind]].erase(ind);

      ar[ind]=u;

      freq[ar[ind]].insert(ind);
      if(ind>1) s[lca(ar[ind],ar[ind-1])].insert(ind);
      if(ind<n) s[lca(ar[ind],ar[ind+1])].insert(ind+1);
    }

    else{
      int l,r,u;
      cin >> l >> r >> u;
      
      auto it = freq[u].lower_bound(l);
      if(it!=freq[u].end() && (*it)<=r){
      	cout << (*it) << " " << (*it) << endl;
      	continue;
      }

      it = s[u].upper_bound(l);

      if(it!=s[u].end() && (*it)<=r){
      	cout << (*it)-1 << " " << (*it) << endl;
      	continue;
      }

      cout << -1 << " " << -1 << endl;
    }

  }
}

int32_t main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  int t=1;//cin >> t;
  while(t--) solve();
}

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 0 / 44