1. Read the network
All links work in both directions. Numbers are travel minutes. No waiting or transfer time is included. These are fictional stations and times, not a real travel planner.
2. Build a route
Begin at Start. Pick a connected station below. You cannot visit a station twice in this puzzle. Reaching Finish ends your route; Undo lets you try another branch.
Available next stops
Build a route, then check it.
3. Compare every complete route
Make a prediction before revealing the answer. This small computer search follows every route that does not revisit a station, adds its link times, and compares complete routes to Finish.
Think like a route planner
A network can be represented as a graph: stations are nodes, railway links are edges, and journey minutes are weights. The goal is the smallest sum of edge weights, not the fewest stations or the smallest next number.
- In Normal service, always pick the smallest available next time. Does that give the fastest complete route?
- Compare Start → Canal → Dunes → Finish with a route that visits more stations. Can more hops take fewer minutes?
- Change to Slow estuary connection. Which part of your original plan should you reconsider?
- In Express link opens, can you find two different routes with the same best time?
Example of adding weights: Start → Bridge → Dunes takes 2 + 9 = 11 minutes in Normal service. It is not a complete answer because you have not reached Finish.
Our exhaustive search is practical only because this network is tiny. It skips revisits: all our link times are positive, so adding a loop cannot improve the time. Larger routing systems can use more efficient shortest-path algorithms. This model leaves out timetables, delays, fares, and accessibility requirements.
Your route stays in this page's memory. It is not saved or uploaded; reloading starts again.