Submission #1244339

#	Time	Username	Problem	Language	Result	Execution time	Memory
1244339		minhpk	Index (COCI21_index)	C++20	110 / 110	683 ms	100044 KiB

index

#include <bits/stdc++.h>
#define int long long
using namespace std;
int a,b;
int z[1000005];
vector <int> pos[1000005];
pair<int,int> q[1000005];
vector <int>  v[1000005];
int res[1000005];
int l[1000005];
int r[1000005];

int bit[1000005];
vector <int> used;
void update(int i,int val){
    i++;
    while (i<=a+64){
         if (bit[i]==0){
             used.push_back(i);
         }
         bit[i]+=val;
         i+=i&-i;
    }
}
int query(int i){
    i++;
    int res=0;
    while (i>0){
         res+=bit[i];
         i-=i&-i;
    }
    return res;
}
void reset(){
    for (auto p:used){
         bit[p]=0;
    }
    used.clear();
}
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> a >> b;
    int max1=0;
    for (int i=1;i<=a;i++){
         cin >> z[i];
         pos[z[i]].push_back(i);
         max1=max(max1,z[i]);
    }
    for (int i=1;i<=b;i++){
         cin >> q[i].first >> q[i].second;
         l[i]=1;
         r[i]=max1;
    }
//    cout << "\n";
    while (true){
        bool check=true;
        for (int i=1;i<=b;i++){
             if (l[i]<=r[i]){
                 check=false;
                 int mid=(l[i]+r[i])/2;
                 v[mid].push_back(i);
             }
        }
        if (check){
            break;
        }
        reset();

        for (int i=max1;i>=1;i--){
             for (auto p:pos[i]){
                  update(p,1);
             }
             for (auto p:v[i]){
                  int sl=query(q[p].second)-query(q[p].first-1);
//                  cout << sl << " " << q[p].first << " " << q[p].second << "\n";
                  if (sl>=i){
                      res[p]=i;
                      l[p]=i+1;
                  }else{
                      r[p]=i-1;
                  }
             }
             v[i].clear();
        }
    }
    for (int i=1;i<=b;i++){
         cout << res[i] << "\n";
    }
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 50 / 50