4. Median of Two Sorted Arrays.py

from typing import List

class Solution:
    def findMedianSortedArrays(self, nums1: List[int], nums2: List[int]) -> float:
        if len(nums1) > len(nums2):
            nums1, nums2 = nums2, nums1
        
        m, n = len(nums1), len(nums2)
        imin, imax, half_len = 0, m, (m + n + 1) // 2
        
        while imin <= imax:
            i = (imin + imax) // 2
            j = half_len - i
            
            if i < m and nums1[i] < nums2[j - 1]:
                imin = i + 1
            elif i > 0 and nums1[i - 1] > nums2[j]:
                imax = i - 1
            else:
                if i == 0: max_of_left = nums2[j - 1]
                elif j == 0: max_of_left = nums1[i - 1]
                else: max_of_left = max(nums1[i - 1], nums2[j - 1])
                
                if (m + n) % 2 == 1:
                    return max_of_left
                
                if i == m: min_of_right = nums2[j]
                elif j == n: min_of_right = nums1[i]
                else: min_of_right = min(nums1[i], nums2[j])
                
                return (max_of_left + min_of_right) / 2.0