Summary

A sequential search is O(n) for ordered and unordered lists.
A binary search of an ordered list is O(log⁡n) in the worst case.
Hash tables can provide constant time searching.
A bubble sort, a selection sort, and an insertion sort are O(n²) algorithms.
A shell sort improves on the insertion sort by sorting incremental sublists. It falls between O(n)and O(n²).
A merge sort is O(n log ⁡n), but requires additional space for the merging process.
A quick sort is O(n log⁡ n), but may degrade to O(n²) if the split points are not near the middle of the list. It does not require additional space.