Submission #570613

#	Time	Username	Problem	Language	Result	Execution time	Memory
570613		SSRS	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1721 ms	94788 KiB

treearray

#include <bits/stdc++.h>
using namespace std;
const int LOG = 18;
struct lowest_common_ancestor{
  vector<int> d;
  vector<vector<int>> pp;
  lowest_common_ancestor(vector<int> &p, vector<int> &d): d(d){
    int N = p.size();
    pp = vector<vector<int>>(LOG, vector<int>(N, -1));
    pp[0] = p;
    for (int i = 0; i < LOG - 1; i++){
      for (int j = 0; j < N; j++){
        if (pp[i][j] != -1){
          pp[i + 1][j] = pp[i][pp[i][j]];
        }
      }
    }
  }
  int lca(int u, int v){
    if (d[u] > d[v]){
      swap(u, v);
    }
    for (int i = 0; i < LOG; i++){
      if (((d[v] - d[u]) >> i & 1) == 1){
        v = pp[i][v];
      }
    }
    if (u == v){
      return u;
    } else {
      for (int i = LOG - 1; i >= 0; i--){
        if (pp[i][u] != pp[i][v]){
          u = pp[i][u];
          v = pp[i][v];
        }
      }
      return pp[0][u];
    }
  }
};
int main(){
  int n, m, q;
  cin >> n >> m >> q;
  vector<vector<int>> E(n);
  for (int i = 0; i < n - 1; i++){
    int u, v;
    cin >> u >> v;
    u--;
    v--;
    E[u].push_back(v);
    E[v].push_back(u);
  }
  vector<int> a(m);
  for (int i = 0; i < m; i++){
    cin >> a[i];
    a[i]--;
  }
  vector<int> p(n, -1);
  vector<int> d(n, 0);
  queue<int> Q;
  Q.push(0);
  while (!Q.empty()){
    int v = Q.front();
    Q.pop();
    for (int w : E[v]){
      if (w != p[v]){
        p[w] = v;
        d[w] = d[v] + 1;
        Q.push(w);
      }
    }
  }
  lowest_common_ancestor T(p, d);
  vector<set<int>> st1(n);
  for (int i = 0; i < m; i++){
    st1[a[i]].insert(i);
  }
  for (int i = 0; i < n; i++){
    st1[i].insert(m);
  }
  vector<set<int>> st2(n);
  for (int i = 0; i < m - 1; i++){
    st2[T.lca(a[i], a[i + 1])].insert(i);
  }
  for (int i = 0; i < n; i++){
    st2[i].insert(m - 1);
  }
  for (int i = 0; i < q; i++){
    int t;
    cin >> t;
    if (t == 1){
      int pos, v;
      cin >> pos >> v;
      pos--;
      v--;
      st1[a[pos]].erase(pos);
      if (pos > 0){
        st2[T.lca(a[pos - 1], a[pos])].erase(pos - 1);
      }
      if (pos < m - 1){
        st2[T.lca(a[pos], a[pos + 1])].erase(pos);
      }
      a[pos] = v;
      st1[a[pos]].insert(pos);
      if (pos > 0){
        st2[T.lca(a[pos - 1], a[pos])].insert(pos - 1);
      }
      if (pos < m - 1){
        st2[T.lca(a[pos], a[pos + 1])].insert(pos);
      }
    }
    if (t == 2){
      int l, r, v;
      cin >> l >> r >> v;
      l--;
      v--;
      auto itr1 = st1[v].lower_bound(l);
      if (*itr1 < r){
        cout << *itr1 + 1 << ' ' << *itr1 + 1 << endl;
      } else {
        auto itr2 = st2[v].lower_bound(l);
        if (*itr2 < r - 1){
          cout << *itr2 + 1 << ' ' << *itr2 + 2 << endl;
        } else {
          cout << -1 << ' ' << -1 << endl;
        }
      }
    }
  }
}

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