Given two sorted arrays nums1 and nums2, find the median of all the elements combined — without necessarily merging them — returned as double its true value so the answer is always a whole number. Merging both arrays and reading off the middle works, but it does far more than necessary: only one or two values near the middle actually matter for the answer, yet the full combined array gets built regardless. The faster approach searches directly for a valid split point instead: a cut in the smaller array, paired with a matching cut in the larger one, such that together they divide all the elements into a "left half" and a "right half" of equal size, with every left value at most every right value. Binary search finds that cut in O(log(min(m,n))) guesses — checking just four boundary values per guess — and once a valid split is found, the median is read directly off those boundaries, with the merge step skipped entirely.