Linear Search

Sequential Scan · O(n)

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Walk every element in order — linear search scans unsorted data in O(n) time using only a single loop and no extra memory.

By the end, you can

Trace linear search step-by-step on a concrete array and count the exact comparisons for both a hit and a miss.
State the best, worst, and average-case time complexities and explain when each arises.
Explain why linear search returns an index, not a value, and what it returns when the target is absent.
Describe the behavior on duplicate values and on an empty array.
Decide when linear search is the appropriate tool versus binary search or a hash table.

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