Submission #754076

#	Time	Username	Problem	Language	Result	Execution time	Memory
754076		nicksms	Dancing Elephants (IOI11_elephants)	C++17	97 / 100	9013 ms	12200 KiB

elephants

#include "elephants.h"
/**
 *      Author:  Nicholas Winschel
 *      Created: 06.06.2023 11:07:24
**/

#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using db=long double;
template<class T> using V=vector<T>;
using vi = V<int>;
using vl = V<ll>;
using pi = pair<int,int>;
#define f first
#define s second
#define sz(x) (int)((x).size())

int n,l;
const int MAXN=150000;
const int BS=387;
int pos[MAXN],j[MAXN],h[MAXN],ord[MAXN],w[MAXN];
vi buck[MAXN/BS + 5];
int cnt = 0;

int llt(const vi &v, int x) {
  if (!sz(v) || pos[v[0]] >= x) return -1;
  int l = 0,r=sz(v);
  while (r-l>1) {
    int m = (l+r)>>1;
    if (pos[v[m]] >= x) r=m;
    else l=m;
  }
  return l;
}

void fixbuck(int i) {
  // cerr << "fb: " << i << endl;
  // for (int x : buck[i]) cerr << x << " ";
  // cerr << endl;
  if (!sz(buck[i])) return;
  j[buck[i][0]]=pos[buck[i][0]]-l,h[buck[i][0]]=1;
  int lp = 0;
  for (int k = 1; k < sz(buck[i]); k++) {
    while (lp < sz(buck[i])-1 && pos[buck[i][lp+1]]<pos[buck[i][k]]-l) lp++;
    if (pos[buck[i][lp]] < pos[buck[i][k]]-l) {
      // cerr << "test" << endl;
      j[buck[i][k]]=j[buck[i][lp]];
      h[buck[i][k]]=h[buck[i][lp]]+1;
    } else {
      j[buck[i][k]]=pos[buck[i][k]]-l;
      h[buck[i][k]]=1;
    }
  }
}

void fixall() {
  // cerr << "REALLOC" << endl;
  int cur = 0;
  for (int i = 0; i <= (n-1)/BS; i++) {
    for (int x : buck[i]) ord[cur++]=x;
    buck[i].resize(BS + 1);
  }
  int c = 0;
  for (int i = 0; i < n; i++) {
    buck[i/BS][c++]=ord[i];
    w[ord[i]]=i/BS;
    if (i == n-1 || (i+1)/BS != i/BS) buck[i/BS].resize(c),c=0,fixbuck(i/BS);
  }
}

void init(int N, int L, int X[])
{
  n = N;
  l = L;
  memcpy(pos,X,N*sizeof(int));
  for (int i = 0; i < N; i++) {
    buck[i/BS].push_back(i);
  }
  fixall();
}

int update(int i, int y)
{
  // cerr << "mov: " << i << " " << y << endl;
  if (cnt++ > BS) fixall(),cnt=0;
  buck[w[i]].erase(find(buck[w[i]].begin(),buck[w[i]].end(),i));
  fixbuck(w[i]);
  pos[i]=y;
  w[i]=0;
  for (int k = 0; k <= (n-1)/BS; k++) {
    if (sz(buck[k]) && pos[buck[k][0]] < pos[i]) w[i]=k;
  }
  int ind = llt(buck[w[i]],pos[i])+1;
  buck[w[i]].insert(buck[w[i]].begin()+ind,i);
  fixbuck(w[i]);
  // for (int i = 0; i < n; i++) {
  //   cerr << "dbg: " << i << " " << pos[i] << " " << j[i] << " " << h[i] << endl; 
  // }
  int cur = 2e9,ret=0;
  for (int i = (n-1)/BS; i >= 0; i--) {
    int ind = llt(buck[i],cur);
    if (ind >= 0) {
      ind=buck[i][ind];
      cur=j[ind],ret += h[ind];
      // cerr << "jmp: " << cur << " " << ret << endl;
    }
  }
  return ret;
}

• Subtask 1: 10 / 10
• Subtask 2: 16 / 16
• Subtask 3: 24 / 24
• Subtask 4: 47 / 47
• Subtask 5: 0 / 3