Submission #787256

#	Time	Username	Problem	Language	Result	Execution time	Memory
787256		trucmai	Ball Machine (BOI13_ballmachine)	C++17	100 / 100	144 ms	54892 KiB

ballmachine

//i_love_aisukiuwu
#include <bits/stdc++.h>
using namespace std;

#ifdef LOCAL
  #include "/home/trucmai/.vim/tools.h"
  #define debug(x...) cerr << "\e[91m"<<__func__<<":"<<__LINE__<<" [" << #x << "] = ["; _print(x); cerr << "\e[39m" << endl;
  #else
  #define debug(x...)
#endif

void open(){
  if(fopen("i.inp","r")){
    freopen("i.inp","r",stdin);
    freopen("o.out","w",stdout);
  }
}

#define ll long long
#define all(a) (a).begin(), (a).end()
#define vi vector<ll>
#define pi pair<ll,ll>
#define pii pair<ll,pair<ll,ll>>
#define fi first
#define se second
#define gcd __gcd
#define mset(a,v) memset(a, v, sizeof(a))
#define endl '\n'
#define spc " "

const int MN1 = 1e6 + 5,MN2 = 1e4 + 5,LOG = 20;
const ll MOD = 1e9 + 7,INF = 1e9;
ll n,q;
ll mx[MN1],h[MN1],tin[MN1];
ll up[MN1][LOG];
bool col[MN1];
vector<ll>adj[MN1]; 
priority_queue<pi,vector<pi>,greater<pi>>pq;

void dfs(ll u){
  mx[u] = u;
  for(ll v : adj[u]){
    h[v] = h[u] + 1;
    up[v][0] = u;
    dfs(v);
    mx[u] = min(mx[u],mx[v]);
  }
}

ll timer = 0;
void dfs2(ll u){
  for(ll v : adj[u]) dfs2(v);
  tin[u] = ++timer; 
}

void solve(){
  cin>>n>>q; 
  for(ll i = 1,p;i <= n;++i){
    cin>>p;
    adj[p].push_back(i);
  }
  dfs(0);
  for(ll i = 1;i < LOG;++i)
    for(ll j = 1;j <= n;++j) up[j][i] = up[up[j][i-1]][i-1];
  for(ll i = 1;i <= n;++i)
    sort(all(adj[i]),[&](ll x,ll y){return mx[x] < mx[y];});
  dfs2(0);
  for(ll i = 1;i <= n;++i){
    // cout<<"DEBUG: "<<i<<spc<<tin[i]<<endl;
    pq.push({tin[i],i}); 
  }
  while(q--){
    ll t,u; cin>>t>>u; 
    if(t == 1){
      ll ptr = 0;
      while(u--){
        ptr = pq.top().se; pq.pop();
        //cout<<"DEBUG: "<<ptr<<endl;
        col[ptr] = true;   
      }
      cout<<ptr<<endl;
    } 
    else{
      ll v = u; 
      for(ll i = LOG-1;i >= 0;--i)
        if(col[up[v][i]]) v = up[v][i]; 
      col[v] = false;
      pq.push({tin[v],v});
      cout<<h[u] - h[v]<<endl;
    }
  }
}

signed main(){
  cin.tie(0) -> sync_with_stdio(0);
  open();
  ll t = 1; //cin>>t;
  while(t--) solve(); 
  //cerr << endl << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
}

Compilation message (stderr)

ballmachine.cpp: In function 'void open()':
ballmachine.cpp:14:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     freopen("i.inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~
ballmachine.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen("o.out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~

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