Binary Search — DSA Visualiser

Speed

💡 Each step eliminates half the remaining elements. This is why it's O(log n) — 1 billion items needs only ≈30 comparisons!

Input

⚠️ Array must be sorted for Binary Search.

Pseudocode

lo = 0, hi = n - 1 while lo <= hi: mid = (lo + hi) / 2 if arr[mid] == target: return mid elif arr[mid] < target: lo = mid + 1 else: hi = mid - 1 return -1

Colour Guide

Mid (Being Compared)

Target Found

Active Search Range

Eliminated (Out of Range)

Pointers

L (left) –

M (mid) –

R (right) –

Step Log

Complexity

Best Case	O(1)
Worst Case	O(log n)
Average	O(log n)
Space	O(1)

⚠️ The array must be sorted for Binary Search to work correctly.