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Search a target in a rotated sorted array with no duplicates. Modified binary search identifies which half is sorted, then checks the target range. O(log n) time.
Determine if you can reach the last index. Greedy: track maximum reachable index. If current position exceeds max reach, return false. O(n) O(1).
Rotate array right by k steps. Triple reverse trick: reverse whole, reverse first k, reverse rest. O(n) time O(1) space.
Find the minimum element in a rotated sorted array with no duplicates. Binary search: the minimum is in the unsorted half. O(log n) time O(1) space.
Find k most frequent elements. Approach 1: min-heap O(n log k). Approach 2: bucket sort O(n). Full 5-language solutions.