From 2edf415e2a8ceb432668d5546885b2d1403bc549 Mon Sep 17 00:00:00 2001
From: Tomasz Polgrabia <tomasz@polgrabia.me>
Date: Mon, 10 Feb 2025 11:50:56 +0100
Subject: [PATCH] Basic tasks with priority queues in java.

---
 current/algorithms/java/Queue.java  | 23 +++++++++++++++++
 current/algorithms/java/Queue2.java | 38 +++++++++++++++++++++++++++++
 current/algorithms/java/README.md   |  3 +++
 3 files changed, 64 insertions(+)
 create mode 100644 current/algorithms/java/Queue.java
 create mode 100644 current/algorithms/java/Queue2.java
 create mode 100644 current/algorithms/java/README.md

diff --git a/current/algorithms/java/Queue.java b/current/algorithms/java/Queue.java
new file mode 100644
index 0000000..0818588
--- /dev/null
+++ b/current/algorithms/java/Queue.java
@@ -0,0 +1,23 @@
+import java.util.*;
+
+public class Program {
+
+  public static void main(String[] args) {
+
+    var arr = new ArrayList<Integer>();
+
+    arr.add(-4);
+
+    var pq = new PriorityQueue<Integer>();
+    pq.add(1);
+    pq.add(5);
+    pq.add(-3);
+    pq.add(-7);
+
+    System.out.printf("Hello World: %d\n", pq.remove());
+    System.out.printf("Hello World: %d\n", pq.remove());
+    System.out.printf("Hello World: %d\n", pq.remove());
+    System.out.printf("Hello World: %d\n", pq.remove());
+  }
+
+}
diff --git a/current/algorithms/java/Queue2.java b/current/algorithms/java/Queue2.java
new file mode 100644
index 0000000..3592c8b
--- /dev/null
+++ b/current/algorithms/java/Queue2.java
@@ -0,0 +1,38 @@
+import java.util.*;
+
+public class Program2 {
+
+  public record Element(
+      int weight) implements Comparable {
+
+    public int compareTo(Object o) {
+
+      if (!(o instanceof Element)) {
+        throw new IllegalArgumentException("Got invalid class to compare: " + o.getClass());
+      }
+
+      Element e = (Element)o;
+
+      return weight - e.weight;
+    }
+
+    public String toString() {
+      return "Element{weight = %d}".formatted(weight);
+    }
+  }
+
+  public static void main(String[] args) {
+
+    var pq = new PriorityQueue<Element>();
+    pq.add(new Element(1));
+    pq.add(new Element(5));
+    pq.add(new Element(-3));
+    pq.add(new Element(-7));
+
+    System.out.printf("Hello World: %s\n", pq.remove());
+    System.out.printf("Hello World: %s\n", pq.remove());
+    System.out.printf("Hello World: %s\n", pq.remove());
+    System.out.printf("Hello World: %s\n", pq.remove());
+  }
+
+}
diff --git a/current/algorithms/java/README.md b/current/algorithms/java/README.md
new file mode 100644
index 0000000..47f0e31
--- /dev/null
+++ b/current/algorithms/java/README.md
@@ -0,0 +1,3 @@
+# How to run
+
+Run it with :!jbang % in vim.