Solve merge-sorted-arrays (again)

InterviewCake.com has a section on Facebook's interview, so I'm attempting to
solve all of the problems on there even if that means I'm resolving
problems. The more practice, the better. Right?

URL: interviewcake.com/facebook-interview-questions

scratch/facebook/interview-cake/merge-sorted-arrays.py

@@ -0,0 +1,30 @@
+def merge_sorted(xs, ys):
+    result = []
+    i = 0
+    j = 0
+    while i < len(xs) and j < len(ys):
+        if xs[i] <= ys[j]:
+            result.append(xs[i])
+            i += 1
+        else:
+            result.append(ys[j])
+            j += 1
+    while i < len(xs):
+        result.append(xs[i])
+        i += 1
+    while j < len(xs):
+        result.append(ys[j])
+        j += 1
+    return result
+
+################################################################################
+# Tests
+################################################################################
+
+xs = [3, 4, 6, 10, 11, 15]
+ys = [1, 5, 8, 12, 14, 19]
+result = merge_sorted(xs, ys)
+print(result)
+assert len(result) == len(xs) + len(ys)
+assert result == [1, 3, 4, 5, 6, 8, 10, 11, 12, 14, 15, 19]
+print("Success!")