Big O Notation
- Tells you number of times an operation is performed
- Doesnt describe duration of operation
- A useful tool for quickly describing how to run time of an algorithm



help you compare algorithm, choose the best one algorithm

Selection sort : check each n toot slow
n = 5
O(n^2)

Quick sort: 
n = 8 
best case O(n log n)
worst case O(n^2)

Merge sort: divide half log n time
O(n log n)


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Linear search:
O(n)

Binary search:
O(n log n)