SG Rail Routing Service

Singapore railway is a railway network with multiline and multiple interchange stations. This simple application expose an API to find and display one or more routes from a specified origin to a specified destination for given journey starting time , ordered by some efficiency heuristic.

Resulted routes have details,

• Steps station FROM - station TO
• Line change
• Total Number of stations to travel
• Total travel time

Designing the solution

Considering stations and connectivity as gra ph theory use case, I've used the Breadth-First Search (BFS) and modified it to get the all possible routes from start to destination. Updated the result path details with the travel time/ wail time considering peak, night and off-peak hours given. Added extra check to avoid circling through the same station again and again.

Assumption made for this the solution

• stations input csv always in the format of below

EW23,Clementi,12 March 1988
EW24,Jurong East,5 November 1988
EW26,Lakeside,5 November 1988

<linecode><number>, <station-name>, <start-date>

Assuming all start dates are in the format of "d MMMM yyyy"

• station names are unique

Prerequisite to run or deploy the service

As, a prerequisite docker should be installed in the environment( assumes using ubuntu)

sudo apt-get update
curl --fail --silent --show-error --location https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo apt-get install software-properties-common
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt-get update
sudo apt-get install -y docker-ce

How to deploy application from docker hub

1. docker pull hmdmph/sg-routing-service:1.0.0
2. docker run -p 8080:8080 hmdmph/sg-routing-service:1.0.0

Click here to go find-routes swagger URL

How to run the application from source

get the source from github

Click here to go find-routes swagger URL

sample payload

Source: Tuas Link
Destination: Redhill
Time: 2021-02-21T10:54:00Z