0004.py

class Solution:
    def findMedianSortedArrays(self, nums1: List[int], nums2: List[int]) -> float:
        A, B = nums1, nums2
        total = len(nums1) + len(nums2)
        half = total // 2
        
        if len(A) > len(B):
            A, B = B, A
        
        l, r = 0, len(A) - 1
        while True:
            i = (l + r) // 2
            j = half - i - 2
            
            a_left = A[i] if i >= 0 else float('-inf')
            a_right = A[i + 1] if i + 1 < len(A) else float('inf')
            b_left = B[j] if j >= 0 else float('-inf')
            b_right = B[j + 1] if j + 1 < len(B) else float('inf')
            
            if b_right >= a_left and a_right >= b_left:
                if total % 2 == 1:
                    return min(a_right, b_right)
                return (min(a_right, b_right) + max(a_left, b_left)) / 2
            elif a_left > b_right:
                r = i - 1
            else:
                l = i + 1