Cheat Sheet

Binary Search Cheat Sheet

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What is Binary Search?

Divide and conquer with logarithmic time complexity.

Trigger Words

When you see these in a problem, think Binary Search:

binary search binary-search search a 2d matrix koko eating bananas search in rotated sorted array find minimum in rotated sorted array time based key-value store median of two sorted arrays

Template Code

def search(nums: List[int], target: int) -> int:
    left, right = 0, len(nums) - 1
    
    while left <= right:
        mid = left + (right - left) // 2
        
        if nums[mid] == target:
            return mid
        elif nums[mid] < target:
            left = mid + 1
        else:
            right = mid - 1
    
    return -1

Complexity

Typical Time	`O(log n)`
Typical Space	`O(1)`

Common Variations

Basic Binary Search
Binary Search with constraints
Optimized Binary Search

Practice Problems

Binary Search medium Search a 2D Matrix medium Koko Eating Bananas medium Search in Rotated Sorted Array medium Find Minimum in Rotated Sorted Array medium

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