Submission #969430

#	Time	Username	Problem	Language	Result	Execution time	Memory
969430		AliHasanli	Index (COCI21_index)	C++17	60 / 110	2530 ms	46540 KiB

index

#include<bits/stdc++.h>
using namespace std;
int a[200005];
vector<int>seg[800005];
void build(int no,int l,int r)
{
    //cout<<"B "<<no<<" "<<l<<" "<<r<<endl;
    if(l==r){seg[no].push_back(a[l]);return;}
    build(2*no,l,(l+r)/2);
    build(2*no+1,(l+r)/2+1,r);
    seg[no].resize(seg[no*2].size()+seg[no*2+1].size());
    merge(seg[2*no+1].begin(), seg[2*no+1].end(), seg[2*no].begin(), seg[2*no].end(), seg[no].begin());
}
int query(int n,int l,int r,int ql,int qr,int h)
{
    //cout<<"A "<<n<<endl;
    if(l>r || ql>qr || r<ql || qr<l)return 0;
    if(ql<=l && r<=qr)
    {
        if(lower_bound(seg[n].begin(),seg[n].end(),h)==seg[n].end())return 0;
        int index=lower_bound(seg[n].begin(),seg[n].end(),h)-seg[n].begin();
        return seg[n].size()-index;
    }
    return query(2*n,l,(l+r)/2,ql,qr,h)+query(2*n+1,(l+r)/2+1,r,ql,qr,h);
}
int ans(int a,int b,int n)
{
    int answer=0;
    int l=1,r=200000;
    int mid;
    while(l<=r)
    {mid=(l+r)/2;
        //cout<<l<<" "<<r<<" "<<mid<<endl;
    if(query(1,1,n,a,b,mid)>=mid)
        answer=max(answer,mid),l=mid+1;
    else r=mid-1;
    }
    return answer;
}
int main()
{
    int n,q;
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    cin>>a[i];
    build(1,1,n);
    //cout<<"C"<<endl;
    while(q--)
    {
        int a,b;
        cin>>a>>b;
        cout<<ans(a,b,n)<<endl;
    }
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 0 / 50