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Pattern Recognition Drill

#56 — Min in rotated sorted array

Medium Binary Search

The Problem

Given a rotated sorted array with unique elements, find the minimum element.

What approach would you use?

Think about it before scrolling down.

Key Signals

Binary Search

Compare a[mid] with a[hi]. If a[mid] > a[hi], rotation point is right. O(log n).

Common Trap

Compare with a[hi] not a[lo]. Comparing with a[lo] doesn't reliably tell you which side the min is on.

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