README
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Example 01 — Basic shortest paths
What it demonstrates
The minimal end-to-end GoGraph flow: build a weighted directed graph
with the mutable adjlist builder, freeze it into an immutable CSR
snapshot, and run a single-source shortest-paths query with
search.Dijkstra. It reads back both the shortest distance and the
reconstructed route to each destination.
Domain / scenario
A tiny road network between five European cities. Each directed edge is a one-way leg with a distance in kilometres:
Lisbon -> Madrid (624)
Lisbon -> Paris (1737)
Madrid -> Paris (1274)
Madrid -> Rome (1969)
Paris -> Rome (1422)
The query is anchored at Lisbon. The interesting case is Rome:
the direct-looking Lisbon -> Paris -> Rome path costs 3159 km, while
Lisbon -> Madrid -> Rome costs only 2593 km — so the route, not just
the distance, is worth printing.
How to run
go run ./examples/01_basic
Expected output
Lisbon -> Madrid : 624 km route: Lisbon -> Madrid
Lisbon -> Paris : 1737 km route: Lisbon -> Paris
Lisbon -> Rome : 2593 km route: Lisbon -> Madrid -> Rome
Key APIs
graph/adjlist.New/AdjList.AddEdge— build the mutable weighted directed graph.graph/adjlist.AdjList.Mapper— translate between city names and compactNodeIDs (Lookup,Resolve).graph/csr.BuildFromAdjList— freeze the builder into an immutable CSR snapshot for analytics.search.Dijkstra— single-source shortest paths over non-negative weights.search.Distances.Distance/search.Distances.Path— read back the cost and reconstruct the route to each node.
Further reading
search— traversal and path-finding package documentationgraph/csr— the immutable CSR snapshot used as the query surfacegraph/adjlist— the mutable adjacency-list builder- Example 02 — property graph — the next example, building on this flow
- docs/examples-standard.md — the standard every example follows
Documentation
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Overview ¶
Example 01_basic — build a small weighted directed graph, snapshot it to a CSR view, and run a single-source shortest-paths query.
For each reachable city it prints both the shortest distance from Lisbon and the route taken (the parent chain reconstructed from the Dijkstra result, resolved back to city names through the adjacency list's mapper).
Sample output: run `go run ./examples/01_basic` and capture the stdout — the output is deterministic for the inputs hard-coded above and serves as the regression baseline a future change should preserve.
Source Files