Add #each_with_priority

lib/pairing_heap.rb

@@ -261,12 +261,20 @@ def get_priority_if_exists(elem)
 
     # Returns enumerator of elements.
     # @note There are no order guarantees.
-    # @return [Enumerator]
+    # @return [Enumerator<Object>]
     def each
       return to_enum(__method__) { size } unless block_given?
       @nodes.each_value { |node| yield node.elem }
     end
 
+    # Returns enumerator of elements.
+    # @note There are no order guarantees.
+    # @return [Enumerator<Array(Object, Object)>]
+    def each_with_priority
+      return to_enum(__method__) { size } unless block_given?
+      @nodes.each_value { |node| yield [node.elem, node.priority] }
+    end
+
     private
 
     include MergePairs
@@ -406,6 +414,14 @@ def each
       NodeVisitor.visit_node(@root) { |x| yield x.elem }
     end
 
+    # @return [Enumerator<Array(object, object)>]
+    # Returns enumerator of elements.
+    # @note There are no order guarantees.
+    def each_with_priority
+      return to_enum(__method__) { size } unless block_given?
+      NodeVisitor.visit_node(@root) { |x| yield [x.elem, x.priority] }
+    end
+
     private
 
     include MergePairs

test/pairing_heap_test.rb

@@ -37,6 +37,20 @@ def included(ancestor)
           end
         end
 
+        describe "#each_with_priority" do
+          it "returns all elements" do
+            1.upto(500) do |i|
+              @queue.push(i)
+            end
+            @queue.pop
+            _(@queue.each_with_priority.to_set).must_equal(Set.new((2..500).map { |x| [x, x] }))
+          end
+
+          it "returns no elements when empty" do
+            _(@queue.each_with_priority.to_a).must_equal([])
+          end
+        end
+
         describe "#peek_with_priority" do
           it "returns tuple with priority" do
             @queue.push(1, 2)