Submission #751302

#	Time	Username	Problem	Language	Result	Execution time	Memory
751302		sofija6	Index (COCI21_index)	C++14	60 / 110	391 ms	95448 KiB

index

#include <bits/stdc++.h>
#define ll long long
#define MAXN 200010
#define MAXV 2000010
using namespace std;
ll p[MAXN],root[MAXV],l[MAXV],r[MAXV],val[MAXV],ind=1;
void Init(ll node,ll lx,ll rx)
{
    if (lx==rx)
        return;
    l[node]=ind++;
    r[node]=ind++;
    ll mid=(lx+rx)/2;
    Init(l[node],lx,mid);
    Init(r[node],mid+1,rx);
}
void Update(ll node,ll pnode,ll lx,ll rx,ll pos,ll vall)
{
    if (lx==rx)
    {
        val[node]=val[pnode]+vall;
        return;
    }
    ll mid=(lx+rx)/2;
    if (pos<=mid)
    {
        l[node]=ind++;
        r[node]=r[pnode];
        Update(l[node],l[pnode],lx,mid,pos,vall);
    }
    else
    {
        l[node]=l[pnode];
        r[node]=ind++;
        Update(r[node],r[pnode],mid+1,rx,pos,vall);
    }
    val[node]=val[l[node]]+val[r[node]];
}
ll Calc(ll node,ll lx,ll rx,ll L,ll R)
{
    if (lx>R || rx<L)
        return 0;
    if (lx>=L && rx<=R)
        return val[node];
    ll mid=(lx+rx)/2;
    return Calc(l[node],lx,mid,L,R)+Calc(r[node],mid+1,rx,L,R);
}
int main()
{
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    ll n,q,L,R;
    cin >> n >> q;
    for (ll i=1;i<=n;i++)
        cin >> p[i];
    root[0]=ind++;
    Init(root[0],1,MAXN);
    for (ll i=1;i<=n;i++)
    {
        root[i]=ind++;
        Update(root[i],root[i-1],1,MAXN,p[i],1);
    }
    while (q--)
    {
        cin >> L >> R;
        ll l=1,r=R-L+1,mid,ans;
        while (l<=r)
        {
            mid=(l+r)/2;
            if (Calc(root[R],1,MAXN,mid,MAXN)-Calc(root[L-1],1,MAXN,mid,MAXN)>=mid)
            {
                ans=mid;
                l=mid+1;
            }
            else
                r=mid-1;
        }
        cout << ans << "\n";
    }
    return 0;
}

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