Input

1 / 12

Speed

Counted 11 characters → 5 distinct symbols. Each becomes a leaf weighted by its frequency.

Frequencies

A:5B:2R:2C:1D:1

Code table

Codes appear once the tree is complete.

huffman.js

1function huffman(text) {

2 const freq = countFrequencies(text);

3 const pq = [...leaves].sort(by freq);

5 while (pq.length > 1) {

6 const a = pq.shift(); // lightest

7 const b = pq.shift(); // 2nd lightest

8 pq.push(merge(a, b));

9 pq.sort(by freq);

10 }

12 const root = pq[0];

13 return assignCodes(root, '');

14}

Type A–Z text or pick a preset · Amber ring = pair being merged · Codes appear once the tree completes

About the Huffman Coding algorithm

Build an optimal prefix-free code by repeatedly merging the two least-frequent nodes. Watch the greedy tree take shape and the codes fall out.

Category: Tree
Difficulty: Medium
Time complexity: O(n log n)
Space complexity: O(n)
Introduced: 1952