tasks a-s

Task/Priority-queue/Ruby/priority-queue.rb

@@ -0,0 +1,51 @@
+class PriorityQueueNaive
+  def initialize
+    @q = Hash.new { |h, k| h[k] = []}
+    @priorities = []
+  end
+
+  def push(priority, item)
+    @q[priority] << item
+    @priorities = @q.keys.sort
+  end
+
+  def pop
+    p = @priorities[0]
+    item = @q[p].shift
+    if @q[p].empty?
+      @q.delete(p)
+      @priorities.shift
+    end
+    item
+  end
+
+  def peek
+    if not empty?
+      @q[@priorities[0]][0]
+    end
+  end
+
+  def empty?
+    @priorities.empty?
+  end
+
+  def inspect
+    @q.inspect
+  end
+end
+
+test = [
+  [6, "drink tea"],
+  [3, "Clear drains"],
+  [4, "Feed cat"],
+  [5, "Make tea"],
+  [6, "eat biscuit"],
+  [1, "Solve RC tasks"],
+  [2, "Tax return"],
+]
+
+pq = PriorityQueueNaive.new
+test.each {|pr, str| pq.push(pr, str) }
+until pq.empty?
+  puts pq.pop
+end