From 4a52a71956a8d46fcb7294ac71734504bb09bcc2 Mon Sep 17 00:00:00 2001
From: S. Solomon Darnell
Date: Fri, 28 Mar 2025 21:52:21 -0500
Subject: two version of R2R are here

---
 .../networkx/algorithms/traversal/beamsearch.py    | 90 ++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 .venv/lib/python3.12/site-packages/networkx/algorithms/traversal/beamsearch.py

(limited to '.venv/lib/python3.12/site-packages/networkx/algorithms/traversal/beamsearch.py')

diff --git a/.venv/lib/python3.12/site-packages/networkx/algorithms/traversal/beamsearch.py b/.venv/lib/python3.12/site-packages/networkx/algorithms/traversal/beamsearch.py
new file mode 100644
index 00000000..23fbe7bb
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/networkx/algorithms/traversal/beamsearch.py
@@ -0,0 +1,90 @@
+"""Basic algorithms for breadth-first searching the nodes of a graph."""
+
+import networkx as nx
+
+__all__ = ["bfs_beam_edges"]
+
+
+@nx._dispatchable
+def bfs_beam_edges(G, source, value, width=None):
+    """Iterates over edges in a beam search.
+
+    The beam search is a generalized breadth-first search in which only
+    the "best" *w* neighbors of the current node are enqueued, where *w*
+    is the beam width and "best" is an application-specific
+    heuristic. In general, a beam search with a small beam width might
+    not visit each node in the graph.
+
+    .. note::
+
+       With the default value of ``width=None`` or `width` greater than the
+       maximum degree of the graph, this function equates to a slower
+       version of `~networkx.algorithms.traversal.breadth_first_search.bfs_edges`.
+       All nodes will be visited, though the order of the reported edges may
+       vary. In such cases, `value` has no effect - consider using `bfs_edges`
+       directly instead.
+
+    Parameters
+    ----------
+    G : NetworkX graph
+
+    source : node
+        Starting node for the breadth-first search; this function
+        iterates over only those edges in the component reachable from
+        this node.
+
+    value : function
+        A function that takes a node of the graph as input and returns a
+        real number indicating how "good" it is. A higher value means it
+        is more likely to be visited sooner during the search. When
+        visiting a new node, only the `width` neighbors with the highest
+        `value` are enqueued (in decreasing order of `value`).
+
+    width : int (default = None)
+        The beam width for the search. This is the number of neighbors
+        (ordered by `value`) to enqueue when visiting each new node.
+
+    Yields
+    ------
+    edge
+        Edges in the beam search starting from `source`, given as a pair
+        of nodes.
+
+    Examples
+    --------
+    To give nodes with, for example, a higher centrality precedence
+    during the search, set the `value` function to return the centrality
+    value of the node:
+
+    >>> G = nx.karate_club_graph()
+    >>> centrality = nx.eigenvector_centrality(G)
+    >>> list(nx.bfs_beam_edges(G, source=0, value=centrality.get, width=3))
+    [(0, 2), (0, 1), (0, 8), (2, 32), (1, 13), (8, 33)]
+    """
+
+    if width is None:
+        width = len(G)
+
+    def successors(v):
+        """Returns a list of the best neighbors of a node.
+
+        `v` is a node in the graph `G`.
+
+        The "best" neighbors are chosen according to the `value`
+        function (higher is better). Only the `width` best neighbors of
+        `v` are returned.
+        """
+        # TODO The Python documentation states that for small values, it
+        # is better to use `heapq.nlargest`. We should determine the
+        # threshold at which its better to use `heapq.nlargest()`
+        # instead of `sorted()[:]` and apply that optimization here.
+        #
+        # If `width` is greater than the number of neighbors of `v`, all
+        # neighbors are returned by the semantics of slicing in
+        # Python. This occurs in the special case that the user did not
+        # specify a `width`: in this case all neighbors are always
+        # returned, so this is just a (slower) implementation of
+        # `bfs_edges(G, source)` but with a sorted enqueue step.
+        return iter(sorted(G.neighbors(v), key=value, reverse=True)[:width])
+
+    yield from nx.generic_bfs_edges(G, source, successors)
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