Submission #492790

#	Time	Username	Problem	Language	Result	Execution time	Memory
492790		pauloamed	Klasika (COCI20_klasika)	C++14	0 / 110	141 ms	19644 KiB

klasika

#include<bits/stdc++.h>
using namespace std;

#define MAXN 200010

struct Node{
  int size, time_created, lazy;
  int c[2];
  Node(int time, int _size = 0):
    size(_size), time_created(time), lazy(0), c({-1, -1}){}
};

struct PersMaxXORTrie{
  vector<Node> nodes;
  // root: nodes[0]
  // todos numeros sao armazenados em nos terminais
  // um no terminal pode manter mais de um numero

  void propagate_xor(int node, int curr_bit){
    if(get_bit(nodes[node].lazy, curr_bit)){
      swap(nodes[node].c[0], nodes[node].c[1]);
    }

    for(int i = 0; i < 2; ++i){
      if(nodes[node].c[i] != -1){
        nodes[nodes[node].c[i]].lazy ^= nodes[node].lazy; 
      }
    }
    nodes[node].lazy = 0;
  }

  void xor_all(int x){
    nodes[0].lazy ^= x;
  }

  PersMaxXORTrie(){
    nodes.push_back(Node(-1));
  }

  bool get_bit(int x, int i){
    return (x >> i) & 1;
  }

  void add(int num, int time, int curr_node = 0, int curr_bit = 31){
    nodes[curr_node].size++;
    if(curr_bit == -1) return;
    propagate_xor(curr_node, curr_bit);

    nodes[curr_node].time_created = min(nodes[curr_node].time_created, time);

    int b = get_bit(num, curr_bit);
    if(nodes[curr_node].c[b] == -1){
      nodes[curr_node].c[b] = nodes.size();
      nodes.push_back(Node(time));
    }

    add(num, time, nodes[curr_node].c[b], curr_bit - 1);
  }

  int query_max(int num, int max_perm_time, int curr_node = 0, int curr_bit = 31){
    // want to max (num ^ x)
    if(curr_bit == -1) return 0; // base recursion case
    propagate_xor(curr_node, curr_bit);

    assert(nodes[curr_node].size > 0); // cant enter an empty node

    int b = !get_bit(num, curr_bit); // target bit (maximize xor)

    if((nodes[curr_node].c[b] != -1) && (nodes[nodes[curr_node].c[b]].time_created <= max_perm_time)){
      return query_max(num, max_perm_time, nodes[curr_node].c[b], curr_bit - 1) + (b << curr_bit);
    }else{
      return query_max(num, max_perm_time, nodes[curr_node].c[!b], curr_bit - 1) + ((!b) << curr_bit);
    }
  }

};


vector<int> v[MAXN];
int dfs_time = 0;
int xor_until[MAXN];
int sz[MAXN];
int w[MAXN];
int beg[MAXN], en[MAXN], ver[MAXN];
int time_added[MAXN];

int preprocess_dfs(int x, int p){
  // xor preffix
  xor_until[x] = xor_until[p] ^ w[x];

  // sack
  ver[dfs_time] = x;
  beg[x] = dfs_time++;
  sz[x] = 1;

  for(auto y : v[x]){
    if(y != p){
      preprocess_dfs(y, x);
      sz[x] += sz[y];
    }
  }

  // sack
  en[x] = dfs_time;
}

map<int, vector<pair<int,int>>> queries; // time, val
map<int, int> ans;

PersMaxXORTrie solve(int x){
  int heavy_child = -1;
  int max_size = -1;

  // cout << 1 << " " << x << " " << d<< endl; 
  for (auto k : v[x]){
    if (sz[k] > max_size){
      max_size = sz[k];
      heavy_child = k;
    }
  }

  // cout << 2 << " " << x << endl;
  PersMaxXORTrie heavy_trie;
  for (auto k : v[x]){
    if(k == heavy_child) heavy_trie = solve(k);
    else solve(k);
  }


  if(heavy_child != -1){
    heavy_trie.xor_all(w[heavy_child]);
    for (auto k : v[x]){
      if (k != heavy_child){
        for(int it = beg[k]; it < en[k]; ++it){
          heavy_trie.add(xor_until[ver[it]] ^ xor_until[x], time_added[ver[it]]);
        }
      }
    }
  }
  // cout << 4 << endl; 

  heavy_trie.add(0, time_added[x]);

  // cout << ">>" << endl;
  for(auto [t, a] : queries[x]){
    ans[t] = a ^ heavy_trie.query_max(a, t);
  }
  // cout << "<<" << endl;

  heavy_trie.add(w[x], time_added[x]);

  return heavy_trie;
}

int main(){
  int next_node = 2;
  int n; cin >> n;
  
  vector<pair<int,pair<int,int>>> q;
  for(int i = 0; i < n; ++i){
    string s; cin >> s;
    if(s[0] == 'A'){
      int par, weight; cin >> par >> weight;

      time_added[next_node] = i;
      w[next_node] = weight;
      v[par].push_back(next_node);

      next_node++;
    }else{
      int start, subtree; cin >> start >> subtree;
      q.push_back({i, {start, subtree}});
    }
  }

  preprocess_dfs(1, 0);

  for(auto [i, ab] : q){
    auto [start, subtree] = ab;
    int val = xor_until[start] ^ xor_until[subtree];
    queries[subtree].push_back({i, val});
  }
  q.clear();

  solve(1);

  for(auto [_, val] : ans) cout << val << "\n";
}

Compilation message (stderr)

klasika.cpp: In constructor 'Node::Node(int, int)':
klasika.cpp:10:57: warning: list-initializer for non-class type must not be parenthesized
   10 |     size(_size), time_created(time), lazy(0), c({-1, -1}){}
      |                                                         ^
klasika.cpp: In function 'int preprocess_dfs(int, int)':
klasika.cpp:105:1: warning: no return statement in function returning non-void [-Wreturn-type]
  105 | }
      | ^
klasika.cpp: In function 'PersMaxXORTrie solve(int)':
klasika.cpp:145:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  145 |   for(auto [t, a] : queries[x]){
      |            ^
klasika.cpp: In function 'int main()':
klasika.cpp:178:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  178 |   for(auto [i, ab] : q){
      |            ^
klasika.cpp:179:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  179 |     auto [start, subtree] = ab;
      |          ^
klasika.cpp:187:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  187 |   for(auto [_, val] : ans) cout << val << "\n";
      |            ^

• Subtask 1: 0 / 11
• Subtask 2: 0 / 22
• Subtask 3: 0 / 33
• Subtask 4: 0 / 44