Python · Theory

Searching Algorithms in Python

Theory

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Linear search walks left to right — works on any list, O(n). Binary search cuts half each time — list must be sorted, O(log n).

If they say binary search, first sentence is “sorted”. Unsorted binary search is wrong.

Searching Algorithms in Python — output — True then 1. Linear membership. Binary search needs a sorted list.

Exam tip

Linear vs binary: sorted or not + complexity.

# Searching Algorithms in Python
a = [70, 90, 80]
print(90 in a)
print(a.index(90) if 90 in a else -1)

Searching Algorithms in Python — output: True then 1. Linear membership. Binary search needs a sorted list.