n_union_and_intersection.py

from typing import Tuple
import numpy as np


def n_union_and_intersection(a: np.ndarray, b: np.ndarray) -> Tuple[int, int]:
    na = len(a)
    nb = len(b)
    ia = 0
    ib = 0

    if na == 0:
        return (nb, 0)
    if nb == 0:
        return (na, 0)

    cu = 2 if a[0] != b[0] else 1
    ci = 0

    ua = False
    ub = False

    while ia < na and ib < nb:
        va = a[ia]
        vb = b[ib]
        eq = va == vb
        lt = va < vb
        gt = va > vb
        ba = ia != na - 1
        bb = ib != nb - 1

        if eq:
            if ua and ub:
                cu += 1
            ci += 1
        else:
            if ua:
                cu += 1
            if ub:
                cu += 1

        ua = False
        ub = False

        if eq:
            if ba:
                ua = True
            if bb:
                ub = True
        elif lt and ba:
            ua = True
        elif gt and bb:
            ub = True
        elif ba:
            ua = True
        elif bb:
            ub = True

        if ua:
            ia += 1
        if ub:
            ib += 1
        if not ua and not ub:
            break

    return (cu, ci)