Binary Search Algorithm Visualizer
Interactive tool to master binary search patterns for coding interviews. Visualize classic O(log n) search, lower bound, and search in rotated arrays step-by-step.
Classic Binary Search
Find the index of the target value in a sorted array. Returns -1 if not found. Target: 7
def binary_search(arr, target):
left, right = 0, len(arr) - 1
while left <= right:
mid = left + (right - left) // 2
if arr[mid] == target:
return mid
elif arr[mid] < target:
left = mid + 1
else:
right = mid - 1
return -1Understanding Binary Search Patterns
Binary search is a fundamental algorithm that finds the position of a target value within a sorted array. By repeatedly dividing the search interval in half, it reduces the time complexity to O(log n), making it exponentially faster than linear search for large datasets. This pattern requires sorted data or a monotonic property.
Three Core Patterns
Classic Binary Search
Standard template to find a target in a sorted array. Returns index or -1 if not found.
Lower/Upper Bound
Finds the first or last occurrence of a target. Crucial for handling duplicates and insertion points.
Rotated Sorted Array
Determines which half is sorted to maintain O(log n) search even after array rotation.
Key Insight
The core principle of binary search is elimination. In each step, you compare the target with the middle element and confidently eliminate half of the remaining search space. This works because of the sorted nature of the data.
How to Use the Visualizer
- Select a algorithm variant (Classic, Lower Bound, Rotated)
- Use Next/Previous buttons to step through the comparison logic
- Watch the Left, Right, and Mid pointers update in real-time
- Observe how the search range (highlighted area) shrinks by half each step
- Use Auto Play to visualize the O(log n) convergence
Practice Problems
Apply what you've learned with these LeetCode problems:
Learn More
Explore our comprehensive binary search tutorials and guides:
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