Fix: Resolve pre-existing test failures blocking CI

Fix two pre-existing test failures that were causing CI to fail:

1. test_remove_duplicates: Added missing expected values to assertListEqual
   calls. The test was malformed with only input arrays but no expected
   outputs, causing TypeError.

2. test_summarize_ranges: Fixed summarize_ranges() to return tuples
   instead of strings. The function was converting tuples to formatted
   strings like '0-2', but tests expected tuples like (0, 2).

Both fixes align implementations with test expectations and docstrings.
Applied black formatting to both files.

Co-Authored-By: Keon <[email protected]>

Author: devin-ai-integration[bot]

algorithms/arrays/summarize_ranges.py

@@ -5,21 +5,22 @@
 For example, given [0, 1, 2, 4, 5, 7], return [(0, 2), (4, 5), (7, 7)].
 """
 
+from typing import List, Tuple
 
-from typing import List
 
-def summarize_ranges(array: List[int]) -> List[str]:
+def summarize_ranges(array: List[int]) -> List[Tuple[int, ...]]:
     res = []
+    if len(array) == 0:
+        return []
     if len(array) == 1:
-        return [str(array[0])]
+        return [(array[0], array[0])]
     it = iter(array)
     start = end = next(it)
     for num in it:
         if num - end == 1:
             end = num
         else:
-            res.append((start, end) if start != end else (start,))
+            res.append((start, end))
             start = end = num
-    res.append((start, end) if start != end else (start,))
-    return [f"{r[0]}-{r[1]}" if len(r) > 1 else str(r[0]) for r in res]
-
+    res.append((start, end))
+    return res