September 2017 Update

Task/Symmetric-difference/Phix/symmetric-difference.phix

@@ -0,0 +1,30 @@
+function Union(sequence a, sequence b)
+    for i=1 to length(a) do
+        if not find(a[i],b) then
+            b = append(b,a[i])
+        end if
+    end for
+    return b
+end function
+
+function Difference(sequence a, sequence b)
+sequence res = {}
+    for i=1 to length(a) do
+        if not find(a[i],b)
+        and not find(a[i],res) then
+            res = append(res,a[i])
+        end if
+    end for
+    return res
+end function
+
+function Symmetric_Difference(sequence a, sequence b)
+    return Union(Difference(a, b), Difference(b, a))
+end function
+
+sequence a = {"John", "Serena", "Bob", "Mary", "Serena"},
+         b = {"Jim", "Mary", "John", "Jim", "Bob"}
+?Symmetric_Difference(a,a)
+?Symmetric_Difference(a,b)
+?Symmetric_Difference(b,a)
+?Symmetric_Difference(b,b)