Submission #786730

#	Time	Username	Problem	Language	Result	Execution time	Memory
786730		vjudge1	Ball Machine (BOI13_ballmachine)	C++17	17.26 / 100	1097 ms	38424 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 = 1e5 + 5,MN2 = 1e4 + 5,LOG = 27;
const ll MOD = 1e9 + 7,INF = 1e9;
ll n,q,p[MN1],root;
ll mx[MN1],h[MN1],sz[MN1];
ll up[MN1][LOG];
bool col[MN1];
vector<ll>adj[MN1]; 

ll timer  = 0;
void dfs(ll u,ll pre){
  mx[u] = u; sz[u] = 1;
  for(ll v : adj[u]){
    if(v == pre) continue; 
    h[v] = h[u] + 1;
    up[v][0] = u;
    for(ll i = 1;i < LOG;++i) up[v][i] = up[up[v][i-1]][i-1];
    dfs(v,u);
    mx[u] = min(mx[u],mx[v]);
    sz[u] += sz[v];
  }
}

ll dfs_upd(ll u,ll cnt){
  for(ll &v : adj[u]){
    if(!col[v]){
      ll tmp = min(cnt,sz[v]),
         x = dfs_upd(v,tmp);
      if(cnt == tmp) return x; 
    } 
  }
  if(cnt > 0) --cnt,col[u] = true;
  return u;
}

void solve(){
  cin>>n>>q; 
  for(ll i = 1;i <= n;++i){
    cin>>p[i];
    if(p[i] == 0){root = i; continue;}
    adj[p[i]].push_back(i);
  }
  dfs(root,0);
  for(ll i = 1;i <= n;++i)
    sort(all(adj[i]),[&](ll x,ll y){
      return mx[x] < mx[y];
    });
  while(q--){
    ll t,u; cin>>t>>u; 
    if(t == 1) cout<<dfs_upd(root,u)<<endl; 
    else{
      ll v = u; 
      for(ll i = LOG;i >= 0;--i)
        if(col[up[v][i]]) v = up[v][i]; 
      col[v] = false;
      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: 3.8461538461538463 / 25
• Subtask 2: 4.285714285714286 / 30
• Subtask 3: 8.571428571428571 / 40
• Subtask 4: 0.5555555555555556 / 5