Merge e7a7cfc into 4724646

Qiskit · May 5, 2022 · 031445b · 031445b
2 parents 4724646 + e7a7cfc
commit 031445b
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Showing 11 changed files with 1,451 additions and 3 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/docs/source/api.rst b/docs/source/api.rst
@@ -31,6 +31,10 @@ Shortest Paths
    retworkx.dijkstra_shortest_path_lengths
    retworkx.all_pairs_dijkstra_shortest_paths
    retworkx.all_pairs_dijkstra_path_lengths
+   retworkx.bellman_ford_shortest_paths
+   retworkx.bellman_ford_shortest_path_lengths
+   retworkx.negative_edge_cycle
+   retworkx.find_negative_cycle
    retworkx.distance_matrix
    retworkx.floyd_warshall
    retworkx.floyd_warshall_numpy
@@ -273,6 +277,8 @@ the functions from the explicitly typed based on the data type.
    retworkx.digraph_all_pairs_dijkstra_shortest_paths
    retworkx.digraph_dijkstra_shortest_path_lengths
    retworkx.digraph_all_pairs_dijkstra_path_lengths
+   retworkx.digraph_bellman_ford_shortest_path_lengths
+   retworkx.digraph_bellman_ford_shortest_path_lengths
    retworkx.digraph_k_shortest_path_lengths
    retworkx.digraph_dfs_edges
    retworkx.digraph_dfs_search
@@ -323,6 +329,8 @@ typed API based on the data type.
    retworkx.graph_all_pairs_dijkstra_shortest_paths
    retworkx.graph_k_shortest_path_lengths
    retworkx.graph_all_pairs_dijkstra_path_lengths
+   retworkx.graph_bellman_ford_shortest_path_lengths
+   retworkx.graph_bellman_ford_shortest_path_lengths
    retworkx.graph_dfs_edges
    retworkx.graph_dfs_search
    retworkx.graph_transitivity
@@ -353,6 +361,7 @@ Exceptions
    retworkx.DAGWouldCycle
    retworkx.NoEdgeBetweenNodes
    retworkx.DAGHasCycle
+   retworkx.NegativeCycle
    retworkx.NoSuitableNeighbors
    retworkx.NoPathFound
    retworkx.NullGraph

diff --git a/releasenotes/notes/bellman-ford-ebeb580222000f56.yaml b/releasenotes/notes/bellman-ford-ebeb580222000f56.yaml
@@ -0,0 +1,11 @@
+---
+features:
+  - |
+    Added new functions to compute negative cycles and the shortest path
+    in graphs with negative edge weights using the Bellman-Ford
+    algorithm with the SPFA heuristic:
+
+     * :func:`retworkx.find_negative_cycle`
+     * :func:`retworkx.bellman_ford_path_lengths`
+     * :func:`retworkx.bellman_ford_shortest_paths`
+     * :func:`retworkx.edge_negative_cycle`
diff --git a/retworkx-core/Cargo.toml b/retworkx-core/Cargo.toml
@@ -12,6 +12,7 @@ keywords = ["graph"]
 
 [dependencies]
 ahash = { version = "0.7.6", default-features = false }
+fixedbitset = "0.4.1"
 petgraph = "0.6.0"
 rayon = "1.5"