Binary Search — Animate | AI Wisdom

← Back to topic
🎞 ANIMATE · Mode 3 of 5 · +100 XP— Binary Search
🎯Init
🔍Compare
✂️Narrow
✅Found
🎯 Next: Test →
Step 1 / 6
Speed
Initialise bounds
Set left=0, right=9 — entire array is search space💡 Analogy
Like opening a dictionary to the exact middle rather than checking every page.
Start with the full sorted array. left points to the first element, right to the last.
Console Output
> arr: [2,5,8,12,16,23,38,56,72,91]
> left=0  right=9  target=23
●binary-search.ts
Initialise boundsL2–3
1function binarySearch(arr: number[], target: number): number {
2  let left = 0;
3  let right = arr.length - 1;
4 
5  while (left <= right) {
6    const mid = Math.floor((left + right) / 2);
7 
8    if (arr[mid] === target) {
9      return mid;        // Found!
10    } else if (arr[mid] < target) {
11      left = mid + 1;    // Search right half
12    } else {
13      right = mid - 1;   // Search left half
14    }
15  }
16 
17  return -1;             // Not found
18}
19 
20// Example:
21const sorted = [2, 5, 8, 12, 16, 23, 38, 56, 72, 91];
22binarySearch(sorted, 23); // → 5
22 lines
Timeline — 6 Steps
Initialise bounds
Set left=0, right=9 — entire array is search space💡 Analogy
Like opening a dictionary to the exact middle rather than checking every page.
Start with the full sorted array. left points to the first element, right to the last.
Console Output
> arr: [2,5,8,12,16,23,38,56,72,91]
> left=0  right=9  target=23

Set left=0, right=9 — entire array is search space

Set left=0, right=9 — entire array is search space

Was this page helpful?

Discussion

Set left=0, right=9 — entire array is search space

Set left=0, right=9 — entire array is search space

Was this page helpful?

Discussion