Submission #947865

#	Time	Username	Problem	Language	Result	Execution time	Memory
947865		nguyennh	Birthday gift (IZhO18_treearray)	C++14	0 / 100	13 ms	23952 KiB

treearray

#include<bits/stdc++.h>
#define el '\n'
using namespace std ;

mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());

const int MN = 2e5 + 5;
const int block_size = 350;

vector<int> adj[MN];
set<int> pos[MN] , heavy_ans[MN];
int a[MN] , st[MN] , en[MN] , timer = 0 , tour[MN] , depth[MN];

void dfs(int u , int p){
  tour[++timer] = u;
  st[timer] = u;
  for ( auto x : adj[u] ){
    if (x == p) continue;
    depth[x] = depth[u] + 1;
    dfs(x , u);
  }
  en[u] = timer;
}

bool is_anc(int u , int p){
  return st[u] >= st[p] && en[u] <= en[p];
}

int32_t main (){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n , m , q;
  cin >> n >> m >> q;
  for ( int i = 1 ; i < n ; i++ ){
    int u , v;
    cin >> u >> v;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  for ( int i = 1 ; i <= m ; i++ ) cin >> a[i];
  for ( int i = 1 ; i <= m ; i++ ){
    pos[a[i]].insert(i);
  }
  vector<int> heavy;
  for ( int i = 1 ; i <= n ; i++ ){
    if (adj[i].size() > block_size) heavy.push_back(i);
  }
  dfs(1 , 0);
  for ( int i = 0 ; i < heavy.size() ; i++ ){
    for ( int j = 1 ; j <= m - 1 ; j++ ){
      if (depth[a[j]] == depth[heavy[i]] + 1){
        if (is_anc(a[j + 1] , heavy[i])) heavy_ans[heavy[i]].insert(j);
      }
    }
  }
  while (q--){
    int type;
    cin >> type;
    if (type == 2){
      int l , r , v;
      cin >> l >> r >> v;
      auto f = pos[v].lower_bound(l);
      if (f != pos[v].end()){
        if (*f <= r){
          cout << *f << ' ' << *f << el;
          continue;
        }
      }
      if (adj[v].size() <= block_size){
        int x = -1 , y = -1;
        for ( int i = 0 ; i < adj[v].size() ; i++ ){
          if (x != -1 && y != -1) break;
          auto it = pos[adj[v][i]].lower_bound(l);
          while (it != pos[adj[v][i]].end()){
            if (*it > r) break;
            if (*it - 1 >= l){
              if (is_anc(a[*it - 1] , v)){
                x = *it , y = *it - 1;
                break;
              }
            }
            if (*it + 1 <= r){
              if (is_anc(a[*it + 1] , v)){
                x = *it , y = *it + 1;
                break;
              }
            }
            ++it;
          }
        }
        if (x > y) swap(x , y);
        cout << x << " " << y << el;
      }
      else {
        auto it = heavy_ans[v].lower_bound(l);
        if (it == heavy_ans[v].end() || *it >= r){
          cout << -1 << " " << -1 << el;
          continue;
        }
        cout << *it << ' ' << *it + 1 << el;
      }
    }
    else {
      int p , v;
      cin >> p >> v;
      pos[a[p]].erase(pos[a[p]].find(p));
      pos[v].insert(p);
      for ( int i = 0 ; i < heavy.size() ; i++ ){
        auto it = heavy_ans[heavy[i]].lower_bound(p);
        if (it != heavy_ans[heavy[i]].end()){
          if (*it == p){
            if (depth[a[*it + 1]] == depth[heavy[i]] + 1){
              if (!is_anc(v , heavy[i])) heavy_ans[heavy[i]].erase(it);
            }
            else {
              if (!is_anc(v , heavy[i]) || depth[v] == depth[heavy[i]] + 1) heavy_ans[heavy[i]].erase(it);
            }
          }
        }
        if (*it == p - 1){
          if (!is_anc(v , heavy[i])) heavy_ans[heavy[i]].erase(it);
        }
        if (depth[a[p - 1]] == depth[heavy[i]] + 1 && is_anc(v , heavy[i])) heavy_ans[heavy[i]].insert(p);
      }
      a[p] = v;
    }
  }
}

Compilation message (stderr)

treearray.cpp: In function 'int32_t main()':
treearray.cpp:49:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |   for ( int i = 0 ; i < heavy.size() ; i++ ){
      |                     ~~^~~~~~~~~~~~~~
treearray.cpp:71:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |         for ( int i = 0 ; i < adj[v].size() ; i++ ){
      |                           ~~^~~~~~~~~~~~~~~
treearray.cpp:108:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  108 |       for ( int i = 0 ; i < heavy.size() ; i++ ){
      |                         ~~^~~~~~~~~~~~~~

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