Submission #231724

#	Time	Username	Problem	Language	Result	Execution time	Memory
231724		border	Ball Machine (BOI13_ballmachine)	C++14	16.11 / 100	210 ms	131076 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];
vector<int> adj[N];
set<pair<int, int>> s;

struct dat {
  int val, node;
  bool operator<(const dat &a) const {
    return val > a.val;
  }
};

int dfs0(int from, int u) {
  priority_queue<dat> pq;
  for (auto v: adj[u]) {
    if (v == from) continue;
    pq.push({dfs0(v, u), v});
  }
  adj[u].clear();
  int ret = u;
  while (!pq.empty()) {
    adj[u].push_back(pq.top().node);
    ret = min(ret, pq.top().val);
    pq.pop();
  }
}

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++)
    for (j = 0; j < 18; j++)
      P[i][j] = -1;
  for (i = 1; i <= n; i++)
    P[i][0] = T[i];
  for (j = 1; j < 18; j++)
    for (i = 1; i <= n; i++)
      if (P[i][j - 1] != -1)
        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(-1, root);
  dfs(-1, 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 dfs0(int, int)':
ballmachine.cpp:45:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
ballmachine.cpp: In function 'int main()':
ballmachine.cpp:72:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &n, &q);
   ~~~~~^~~~~~~~~~~~~~~~~
ballmachine.cpp:75:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &x);
     ~~~~~^~~~~~~~~~
ballmachine.cpp:84:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &ty, &v);
     ~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 25
• Subtask 2: 6.428571428571429 / 30
• Subtask 3: 8.571428571428571 / 40
• Subtask 4: 1.1111111111111112 / 5