Submission #231757

#	Time	Username	Problem	Language	Result	Execution time	Memory
231757		border	Ball Machine (BOI13_ballmachine)	C++14	100 / 100	179 ms	35820 KiB

ballmachine

#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp> // Common file
// #include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update
 
using namespace std;
// using namespace __gnu_pbds;
 
#define debug(s) cerr << #s << " = " << s << '\n'
#define all(v) (v).begin(), (v).end()
#define mem(a,val) memset(a, val, sizeof a)
 
#define ff first
#define ss second
typedef long long ll;
 
// typedef tree<pair<int, int>,null_type,less<pair<int, int>>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
 
const int N = 100010;
 
int n, qu, ptr, root;
int T[N], P[N][20], L[N], col[N], val[N];
vector<int> adj[N], g[N];

struct dat {
  int va, node;
  bool operator < (const dat &a) const {
    return va > a.va;
  }
};
 
priority_queue<dat> pq;
 
int dfs0(int from, int u) {
  priority_queue<dat> q;
  for (auto v: g[u]) {
    if (v == from) continue;
    q.push({dfs0(u, v), v});
  }
  int ret = u;
  while (!q.empty()) {
    adj[u].push_back(q.top().node);
    ret = min(ret, q.top().va);
    q.pop();
  }
  return ret;
}
 
void dfs(int from, int u) {
  T[u] = from;
  for (auto v: adj[u]) {
    if (v == from) continue;
    dfs(u, v);
  }
  val[u] = ptr;
  pq.push({ptr++, u});
}
 
void init() {
  int i, j;
  for (i = 1; i <= n; i++)
    P[i][0] = T[i];
  
  for (j = 1; j < 18; j++)
    for (i = 1; i <= n; i++)
      P[i][j] = P[P[i][j - 1]][j - 1];
}
 
 
int main() {
  scanf("%d %d", &n, &qu);
  for (int i = 1; i <= n; ++i) {
    int x;
    scanf("%d", &x);
    if (x == 0) root = i;
    g[x].push_back(i);
  }
  dfs0(0, root);
  dfs(0, root);
  init();
  while (qu--) {
    int ty, v;
    scanf("%d %d", &ty, &v);
    if (ty == 1) {
      int ret;
      while (v--) {
        int curnode = pq.top().node;
        col[curnode] = 1;
        ret = curnode;
        pq.pop();
      }
      printf("%d\n", ret);
    }
    else {
      int ret = 0;
      for (int i = 16; i >= 0; --i) {
        if (col[P[v][i]]) {
          ret += (1 << i);
          v = P[v][i];
        }
      }
      col[v] = 0;
      pq.push({val[v], v});
      printf("%d\n", ret);
    }
  }
}

Compilation message (stderr)

ballmachine.cpp: In function 'int main()':
ballmachine.cpp:70:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &n, &qu);
   ~~~~~^~~~~~~~~~~~~~~~~~
ballmachine.cpp:73:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &x);
     ~~~~~^~~~~~~~~~
ballmachine.cpp:82:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &ty, &v);
     ~~~~~^~~~~~~~~~~~~~~~~~

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