From 851b2cc0bbd3f8c33f04350d145582de8d5d600f Mon Sep 17 00:00:00 2001
From: Matej Focko <mfocko@redhat.com>
Date: Mon, 8 Aug 2022 19:21:21 +0200
Subject: [PATCH] =?UTF-8?q?4kyu:=20add=20=E2=80=9EHamming=20Numbers?=
 =?UTF-8?q?=E2=80=9C?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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Signed-off-by: Matej Focko <mfocko@redhat.com>
---
 4kyu/hamming_numbers/solution.java | 26 ++++++++++++++++++++++++++
 README.md                          |  1 +
 2 files changed, 27 insertions(+)
 create mode 100644 4kyu/hamming_numbers/solution.java

diff --git a/4kyu/hamming_numbers/solution.java b/4kyu/hamming_numbers/solution.java
new file mode 100644
index 0000000..8db0c7f
--- /dev/null
+++ b/4kyu/hamming_numbers/solution.java
@@ -0,0 +1,26 @@
+import java.util.PriorityQueue;
+
+public class Hamming {
+    private static void update(PriorityQueue<Long> q, long n) {
+        q.add(2*n);
+        q.add(3*n);
+        q.add(5*n);
+    }
+
+    public static long hamming(int n) {
+        PriorityQueue<Long> cache = new PriorityQueue<>();
+        update(cache, 1);
+
+        long smallest = 1;
+        for (int i = 1; i < n; i++) {
+            smallest = cache.poll();
+            while (cache.peek() == smallest) {
+                cache.poll();
+            }
+
+            update(cache, smallest);
+        }
+
+        return smallest;
+    }
+}
diff --git a/README.md b/README.md
index 799aa79..510ff54 100644
--- a/README.md
+++ b/README.md
@@ -56,6 +56,7 @@
 ### Java
 
 - [Sum of Intervals](https://www.codewars.com/kata/52b7ed099cdc285c300001cd) - [solution](4kyu/sum_of_intervals)
+- [Hamming Numbers](https://www.codewars.com/kata/526d84b98f428f14a60008da) - [solution](4kyu/hamming_numbers)
 
 ## 5 kyu