Submission #231761

#	Time	Username	Problem	Language	Result	Execution time	Memory
231761		border	Ball Machine (BOI13_ballmachine)	C++14	100 / 100	233 ms	28348 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, q, ptr, root;
int T[N], P[N][20], col[N], val[N], sub[N];
vector<int> adj[N];
set<pair<int, int>> s;
 
bool cmp(int A, int B) {
  return sub[A] < sub[B];
}
 
void dfs0(int from, int u) {
  sub[u] = u;
  for (auto v: adj[u]) {
    if (v == from) continue;
    dfs0(u, v);
    sub[u] = min(sub[u], sub[v]);
  }
  sort(all(adj[u]), cmp);
}
 
void dfs(int from, int u) {
  T[u] = from;
  for (auto v: adj[u]){
    if (v == from) continue;
    dfs(u, v);
  }
  val[u] = ptr;
  s.insert({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, &q);
  for (int i = 1; i <= n; ++i) {
    int x;
    scanf("%d", &x);
    if (x == 0) root = i;
    adj[x].push_back(i);
  }
  dfs0(0, root);
  dfs(0, root);
  init();
  while (q--) {
    int ty, v;
    scanf("%d %d", &ty, &v);
    if (ty == 1) {
      int ret;
      while (v--) {
        int node = (*s.begin()).ss;
        col[node] = 1;
        ret = node;
        s.erase({val[node], node});
      }
      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;
      s.insert({val[v], v});
      printf("%d\n", ret);
    }
  }
}

Compilation message (stderr)

ballmachine.cpp: In function 'int main()':
ballmachine.cpp:60:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &n, &q);
   ~~~~~^~~~~~~~~~~~~~~~~
ballmachine.cpp:63:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &x);
     ~~~~~^~~~~~~~~~
ballmachine.cpp:72:10: 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