solve bead sort

Author: AryanJadhav15

sorts/bead_sort.py

@@ -3,9 +3,12 @@
 https://en.wikipedia.org/wiki/Bead_sort
 """
 
+from itertools import pairwise
 
 def bead_sort(sequence: list) -> list:
     """
+    Sorts a list of non-negative integers using bead sort.
+
     >>> bead_sort([6, 11, 12, 4, 1, 5])
     [1, 4, 5, 6, 11, 12]
 
@@ -32,13 +35,29 @@ def bead_sort(sequence: list) -> list:
 
     if any(not isinstance(x, int) or x < 0 for x in sequence):
         raise TypeError("Sequence must be list of non-negative integers")
-    for i, (rod_upper, rod_lower) in enumerate(zip(sequence, sequence[1:])):
-        if rod_upper > rod_lower:
-            sequence[i] -= rod_upper - rod_lower
-            sequence[i + 1] += rod_upper - rod_lower
-    return sequence
+
+    # Early return for empty list
+    if not sequence:
+        return []
+
+    max_value = max(sequence)
+    beads = [[0] * len(sequence) for _ in range(max_value)]
+
+    # Drop beads
+    for i, num in enumerate(sequence):
+        for j in range(num):
+            beads[j][i] = 1
+
+    # Let beads "fall"
+    for row in beads:
+        count = sum(row)
+        for i in range(len(row)):
+            row[i] = 1 if i < count else 0
+
+    # Read off sorted sequence
+    return [sum(beads[j][i] for j in range(max_value)) for i in range(len(sequence))]
 
 
 if __name__ == "__main__":
     assert bead_sort([5, 4, 3, 2, 1]) == [1, 2, 3, 4, 5]
-    assert bead_sort([7, 9, 4, 3, 5]) == [3, 4, 5, 7, 9]
+    assert bead_sort([7, 9, 4, 3, 5]) == [3, 4, 5, 7, 9]