Submission #679617

#	Time	Username	Problem	Language	Result	Execution time	Memory
679617		peijar	Ball Machine (BOI13_ballmachine)	C++17	100 / 100	316 ms	31428 KiB

ballmachine

#include <bits/stdc++.h>
#include <sys/ucontext.h>
#define int long long
using namespace std;

namespace std {
template <typename T> ostream &operator<<(ostream &out, const vector<T> &vec) {
  out << "[";
  for (int i = 0; i < (int)vec.size(); ++i) {
    out << vec[i];
    if (i + 1 < (int)vec.size())
      out << ", ";
  }
  return out << "]";
}
} // namespace std

void dbg_out() { cout << endl; }
template <typename Head, typename... Tail> void dbg_out(Head H, Tail... T) {
  cout << ' ' << H;
  dbg_out(T...);
}

#ifdef DEBUG
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

const int MAXN = 1e5;
const int MAXP = 20;

vector<int> adj[MAXN];
int par[MAXP][MAXN];
int Time;
int order[MAXN];
int depth[MAXN];
int smallestSub[MAXN];

void init(int u, int p) {
  smallestSub[u] = u;
  for (int v : adj[u])
    if (v != p) {
      init(v, u);
      smallestSub[u] = min(smallestSub[u], smallestSub[v]);
    }
}

void dfs(int u, int p) {
  par[0][u] = p;
  for (int i = 0; i < MAXP - 1; ++i)
    par[i + 1][u] = par[i][par[i][u]];
  sort(adj[u].begin(), adj[u].end(),
       [&](int s, int t) { return smallestSub[s] < smallestSub[t]; });
  for (int v : adj[u]) {
    depth[v] = 1 + depth[u];
    dfs(v, u);
  }
  order[u] = Time++;
}

signed main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  int nbSommet, nbRequetes;
  cin >> nbSommet >> nbRequetes;

  int root = -1;
  for (int i = 0; i < nbSommet; ++i) {
    int p;
    cin >> p;
    --p;
    if (p != -1)
      adj[p].push_back(i);
    else
      root = i;
  }

  init(root, root);
  dfs(root, root);

  auto compare = [&](int u, int v) { return order[u] > order[v]; };

  vector<bool> isFilled(nbSommet);
  priority_queue<int, vector<int>, decltype(compare)> pq(compare);

  for (int u = 0; u < nbSommet; ++u)
    pq.push(u);
  for (int iRequete = 0; iRequete < nbRequetes; ++iRequete) {
    int t, x;
    cin >> t >> x;
    if (t == 1) {
      int u = -1;
      for (int i = 0; i < x; ++i) {
        u = pq.top();
        pq.pop();
        isFilled[u] = true;
      }
      cout << u + 1 << '\n';
    } else {
      --x;
      assert(isFilled[x]);
      int u = x;
      for (int p = MAXP - 1; p >= 0; --p)
        if (isFilled[par[p][x]])
          x = par[p][x];
      isFilled[x] = false;
      pq.emplace(x);
      cout << depth[u] - depth[x] << '\n';
    }
  }
}

• Subtask 1: 25 / 25
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40
• Subtask 4: 5 / 5