algo.SSpaths - Single Source Paths

The algo.SSpaths procedure returns all shortest paths from a source node to multiple reachable nodes, subject to constraints like cost, path length, and number of paths to return.

Syntax 

CALL algo.SSpaths({
  sourceNode: <node>,
  relTypes: [<relationship_type>],
  weightProp: <property>,         // optional
  costProp: <property>,           // optional
  maxCost: <int>,                 // optional
  maxLen: <int>,                  // optional
  relDirection: "outgoing",      // or "incoming", "both"
  pathCount: <int>
})
YIELD path, pathWeight, pathCost

Parameters

Name Type Description
sourceNode Node Starting node
relTypes Array List of relationship types to follow
weightProp String Property to minimize along the path (e.g., dist, time)
costProp String Property to constrain the total value (optional)
maxCost Integer Upper bound on total cost (optional)
maxLen Integer Max number of relationships in the path (optional)
relDirection String Traversal direction (outgoing, incoming, both)
pathCount Integer Number of paths to return (0 = all shortest, 1 = default, n = max number of results)

Returns

Name Type Description
path Path Discovered path from source to target
pathWeight Integer Sum of the weightProp across the path
pathCost Integer Sum of the costProp across the path (if used)

Examples:

Lets take this Road Network Graph as an example:

Road network

Example: All Shortest Paths by Distance (up to 10 km) 

MATCH (a:City{name:'A'})
CALL algo.SSpaths({
  sourceNode: a,
  relTypes: ['Road'],
  costProp: 'dist',
  maxCost: 10,
  pathCount: 1000
})
YIELD path, pathCost
RETURN pathCost, [n in nodes(path) | n.name] AS pathNodes
ORDER BY pathCost

Expected Result:

| pathCost | pathNodes |
|———-| ———- | | 2 | [A, D] | | 3 | [A, B] | | 6 | [A, D, C] | | 7 | [A, D, E] | | 8 | [A, B, D] | | 8 | [A, C] | | 10 | [A, B, E] |

Example: Top 5 Shortest Paths from A by Distance 

MATCH (a:City{name:'A'})
CALL algo.SSpaths({
  sourceNode: a,
  relTypes: ['Road'],
  weightProp: 'dist',
  pathCount: 5
})
YIELD path, pathWeight, pathCost
RETURN pathWeight, pathCost, [n in nodes(path) | n.name] AS pathNodes
ORDER BY pathWeight

Expected Result:

| pathWeight | pathCost | pathNodes |
| ———–|———-| ———- | | 2 | 1 | [A, D] | | 3 | 1 | [A, B] | | 6 | 2 | [A, D, C] | | 7 | 2 | [A, D, E] | | 8 | 1 | [A, C] |