Add unit tests and fix algorithm.

Author: deepakhb2

union-find/quick-union/quick_union.rb

@@ -24,16 +24,7 @@ def union(p, q)
     pr = root(p)
     qr = root(q)
     unless(pr == qr)
-      @values[pr] = qr
+      @values[qr] = @values[pr]
     end    
   end
-end
-
-qf = QuickUnion.new(10)
-p qf.values
-qf.union(4, 3)
-p qf.values
-qf.union(9, 8)
-p qf.values
-qf.union(4, 8)
-p qf.values
+end

union-find/quick-union/quick_union_spec.rb

@@ -1,9 +1,39 @@
 require_relative './quick_union'
 
 RSpec.describe QuickUnion do
+  let(:quick_union) { QuickUnion.new(10) }
+
   it "Create array with values assigned to its index" do
-    qf = QuickUnion.new(10)
-    expect(qf.size).to eq(10)
-    expect(qf.values.size).to eq(10)
+    expect(quick_union.size).to eq(10)
+    expect(quick_union.values.size).to eq(10)
+  end
+
+  it "Check if two elements are connected" do
+    expect(quick_union.connected(0, 1)).to eq(false)
+  end
+
+  it "Test the algorithm" do
+    quick_union.union(4, 3)
+    expect(quick_union.values).to eq([0, 1, 2, 4, 4, 5, 6, 7, 8, 9])
+    quick_union.union(9, 8)
+    expect(quick_union.values).to eq([0, 1, 2, 4, 4, 5, 6, 7, 9, 9])
+    quick_union.union(9, 7)
+    expect(quick_union.values).to eq([0, 1, 2, 4, 4, 5, 6, 9, 9, 9])
+    quick_union.union(0, 1)
+    expect(quick_union.values).to eq([0, 0, 2, 4, 4, 5, 6, 9, 9, 9])
+    quick_union.union(6, 7)
+    expect(quick_union.values).to eq([0, 0, 2, 4, 4, 5, 6, 9, 9, 6])
+  end
+
+  it "Get the root element of an element" do
+    quick_union.union(6, 7)
+    expect(quick_union.root(7)).to eq(6)
+  end
+
+  it "Check if two elements are connected" do
+    quick_union.union(0, 1)
+    quick_union.union(1, 2)
+    quick_union.union(2, 3)
+    expect(quick_union.connected(0, 3)).to eq(true)
   end
 end