From 98431e2ec312e4db8fd9b7b0e6b397007310f630 Mon Sep 17 00:00:00 2001
From: putku45 <putku2610@gmail.com>
Date: Tue, 10 Mar 2026 10:56:28 +0530
Subject: [PATCH 1/2] feat: add Huffman Coding greedy algorithm implementation

---
 .../greedyalgorithms/HuffmanCoding.java       | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 src/main/java/com/thealgorithms/greedyalgorithms/HuffmanCoding.java

diff --git a/src/main/java/com/thealgorithms/greedyalgorithms/HuffmanCoding.java b/src/main/java/com/thealgorithms/greedyalgorithms/HuffmanCoding.java
new file mode 100644
index 000000000000..fc6c67d5d54a
--- /dev/null
+++ b/src/main/java/com/thealgorithms/greedyalgorithms/HuffmanCoding.java
@@ -0,0 +1,47 @@
+package com.thealgorithms.greedyalgorithms;
+
+import java.util.PriorityQueue;
+
+/**
+ * Huffman Coding Algorithm
+ * Greedy algorithm used for optimal prefix codes.
+ */
+public class HuffmanCoding {
+
+    static class Node implements Comparable<Node> {
+        char character;
+        int frequency;
+        Node left;
+        Node right;
+
+        Node(char character, int frequency) {
+            this.character = character;
+            this.frequency = frequency;
+        }
+
+        public int compareTo(Node other) {
+            return this.frequency - other.frequency;
+        }
+    }
+
+    public static Node buildHuffmanTree(char[] chars, int[] freq) {
+        PriorityQueue<Node> pq = new PriorityQueue<>();
+
+        for (int i = 0; i < chars.length; i++) {
+            pq.add(new Node(chars[i], freq[i]));
+        }
+
+        while (pq.size() > 1) {
+            Node left = pq.poll();
+            Node right = pq.poll();
+
+            Node parent = new Node('\0', left.frequency + right.frequency);
+            parent.left = left;
+            parent.right = right;
+
+            pq.add(parent);
+        }
+
+        return pq.poll();
+    }
+}

From 1b6caf971b13d13bf5dfa581d4a4645a66c2a3a5 Mon Sep 17 00:00:00 2001
From: putku45 <putku2610@gmail.com>
Date: Tue, 10 Mar 2026 11:36:23 +0530
Subject: [PATCH 2/2] feat: add Huffman Coding greedy algorithm implementation

Added Huffman Coding algorithm implementation.

Huffman Coding is a greedy algorithm used for optimal prefix coding and data compression.

Reference:
https://en.wikipedia.org/wiki/Huffman_coding
---
 .../thealgorithms/greedyalgorithms/HuffmanCoding.java | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/thealgorithms/greedyalgorithms/HuffmanCoding.java b/src/main/java/com/thealgorithms/greedyalgorithms/HuffmanCoding.java
index fc6c67d5d54a..4839bafa9a02 100644
--- a/src/main/java/com/thealgorithms/greedyalgorithms/HuffmanCoding.java
+++ b/src/main/java/com/thealgorithms/greedyalgorithms/HuffmanCoding.java
@@ -4,7 +4,13 @@
 
 /**
  * Huffman Coding Algorithm
- * Greedy algorithm used for optimal prefix codes.
+ *
+ * Greedy algorithm used for optimal prefix coding and data compression.
+ *
+ * Time Complexity: O(n log n)
+ * Space Complexity: O(n)
+ *
+ * https://en.wikipedia.org/wiki/Huffman_coding
  */
 public class HuffmanCoding {
 
@@ -19,8 +25,9 @@ static class Node implements Comparable<Node> {
             this.frequency = frequency;
         }
 
+        @Override
         public int compareTo(Node other) {
-            return this.frequency - other.frequency;
+            return Integer.compare(this.frequency, other.frequency);
         }
     }