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Functions & basics

Reusable building blocks — parameters, returns, scope, and clear function design.

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Functions & basics easy

How to implement binary search in Python

Standalone binary search function that returns the index of a target in a sorted list, or -1 if not found.

binary search algorithms search
Python 
def binary_search(arr, target):
    left, right = 0, len(arr) - 1
    
    while left <= right:
        mid = (left + right) // 2
        if arr[mid] == target:
            return mid
        elif arr[mid] < target:
            left = mid + 1
        else:
            right = mid - 1
    
    return -1

if __name__ ==…
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