Shared code

#include <bits/stdc++.h>
using pii=std::pair<int,int>;
using namespace std;

const int maxn = 2e5 + 5, maxbit = 17;

int n, x[maxn], p, bit[maxn];

void add(int idx, int val)
{
    for(++idx; idx < maxn; idx += idx & -idx)
        bit[idx] += val;
}

int get(int idx)
{
    int cursum = 0;
    for(++idx; idx > 0; idx -= idx & -idx)
        cursum += bit[idx];
    return cursum;
}

int get_fi_pos(int val)
{
    int lo = 0, hi = n - 1, mid;
    while(lo < hi)
    {
        mid = (lo + hi) / 2;
        if(get(mid) >= val)
            hi = mid;
        else
            lo = mid + 1;
    }
    assert(lo == hi);
    return lo;
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    for(int i = 0; i < n; i++)
    {
        cin >> x[i];
        add(i, 1);
    }
    for(int i = 0; i < n; i++)
    {
        cin >> p;
        int pos = get_fi_pos(p);
        cout << x[pos] << " ";
        add(pos, -1);
    }
    cout << "\n";
    return 0;
}