add merge_nodes_cycle func

cidr4_merger.py

@@ -183,6 +183,20 @@ def merge_nodes_recursion(nodes: list[Node], required_len: int) -> list[Node]:
     return merge_nodes_recursion(new_nodes, required_len)
 
 
+def merge_nodes_cycle(nodes_to_merge: list[Node], required_len: int) -> list[Node]:
+    nodes = [x for x in nodes_to_merge]
+    while not len(nodes) <= required_len:
+        groups = make_groups(nodes)
+        neighbours, singles = find_neighbours_singles(groups)
+        if neighbours:
+            nodes = merge_neighbors(nodes, neighbours)
+        elif singles:
+            nodes = lift_lonely_node(nodes, singles)
+        else:
+            raise Cidr4MergerError("Invalid case!")
+    return nodes
+
+
 def main():
     file = "cidr4.txt"
     required_len = 20
@@ -191,8 +205,9 @@ def main():
     nodes = list(map(cidr4_to_node, data))
 
     nodes = sort_nodes(nodes)
-    # merged_nodes = merge_nodes(nodes, required_len)
-    merged_nodes = merge_nodes_recursion(nodes, required_len)
+    # merged_nodes = merge_nodes_deprecated(nodes, required_len)
+    # merged_nodes = merge_nodes_recursion(nodes, required_len)
+    merged_nodes = merge_nodes_cycle(nodes, required_len)
 
     cidr4s = []
     sum_added_ips = 0

tests/test_cidr4_merger.py

@@ -15,6 +15,7 @@ from cidr4_merger import (
     merge_neighbors,
     merge_nodes_deprecated,
     merge_nodes_recursion,
+    merge_nodes_cycle,
     reduce_nodes,
     sort_nodes,
 )
@@ -351,3 +352,29 @@ def test_merge_nodes_recursion():
         )
     assert exc_info.type is Cidr4MergerError
     assert str(exc_info.value) == "The top of the tree has no parent!"
+
+
+def test_merge_nodes_cycle():
+    assert merge_nodes_cycle(
+        [
+            (0, 2, 12, 0),
+            (2147483648, 2, 1, 2147483648),
+            (3221225472, 2, 2, 2147483648),
+        ],
+        2,
+    ) == [
+        (2147483648, 1, 3, 0),
+        (0, 2, 12, 0),
+    ]
+
+    with pytest.raises(Exception) as exc_info:
+        merge_nodes_cycle(
+            [
+                (0, 2, 12, 0),
+                (2147483648, 2, 1, 2147483648),
+                (3221225472, 2, 2, 2147483648),
+            ],
+            1,
+        )
+    assert exc_info.type is Cidr4MergerError
+    assert str(exc_info.value) == "The top of the tree has no parent!"