Submission #1308539

#	Time	Username	Problem	Language	Result	Execution time	Memory
1308539		nikaa123	Dancing Elephants (IOI11_elephants)	C++20	97 / 100	9088 ms	15024 KiB

elephants

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

const int M = 150005;
const int B = 500;
int n,ll;
int a[M];
int t[M];
int fix[M];
int cur;
set<pair<int,int>> s;
vector <vector<pair<int,int>>> v(605);
pair <int,int> nxt[M];
int nb = (n-1+B-1)/B;
int op;

void calc(int j) {
    if (v[j].empty()) return;
    int r = v[j].size()-1;
    for (int i = v[j].size()-1; i >= 0; i--) {
      int cur = v[j][i].first + ll;
      while (r > i && v[j][r].first > cur) r--;
      if (r == v[j].size()-1) {
        nxt[v[j][i].second] = {1,cur};
        continue;
      }
      nxt[v[j][i].second] = {nxt[v[j][r+1].second].first+1,nxt[v[j][r+1].second].second};
    }
}

void solve() {
  
    for (int i = 0; i <= 500; i++) {
      v[i].clear();
    }
    s.clear();
    for (int i = 0; i < n; i++) t[i] = INT_MAX;
    pair<int,int> pos[M];
    for (int i = 0; i < n; i++) {
        pos[i] = {a[i],i};
    }
    sort(pos,pos+n);
    for (int i = 0; i < n; i++) {
        s.insert(pos[i]);
        v[i/B].push_back(pos[i]);
        fix[pos[i].second] = i/B;
    }
    nb = (n + B - 1) / B;
    for (int i = 0; i < nb; i++) {
        calc(i);
    }
    op = 0;

}

int getans() {
    int cur = -1;
    int res = 0;
    auto it = s.upper_bound({cur,-1});
    while (it != s.end()) {
        int id = (*it).second;
        res += nxt[id].first;
        it = s.upper_bound({nxt[id].second,1000000005});
    }
    return res;
}

void remove(int x) {

    pair<int,int> res = {a[x],x};
    int j = fix[x];
    s.erase(res);
    auto it = find(v[j].begin(),v[j].end(),res);
    v[j].erase(it);
    calc(j);

}

void add(int x, int pos) {

    a[x] = pos;
    int j = max(0, nb - 1);
    for (int i = 0; i < nb - 1; i++) {
        if (!v[i].empty() && pos <= v[i].back().first) {
            j = i;
            break;
        }
    }
    s.insert({a[x],x});
    v[j].push_back({a[x],x});
    sort(v[j].begin(),v[j].end()); 
    fix[x] = j;
    calc(j);
    if (++op>=B) {
        solve();
        return;
    }
    
  
}

void init(int N, int L, int X[]) {
    n = N; ll = L;
    nb = (n-1+B-1)/B;
    for (int i = 0; i < n; i++) {
        a[i] = X[i];
    }
    solve();
}

int update(int i, int y) {
    remove(i);
    add(i,y);
    int res = getans();
    return res;
}

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