Link Station Finder

Description

This application simulates a map of coordinates with link stations and devices on it, and determines whether a device at a given position is within the reach of a link station, and picks up the link station with the strongest connection available. Each link stations has a set of coordinates and reach that indicates how strong the signal is and how long it can reach a device. The power of the connection between the device and the link station grows exponentially the shorter the distance gets.

Running the application

Link Station Finder is a command line interface program built with Node Package Manager and TypeScript. It assumes that Node.js is installed onto the computer running it.

After downloading or cloning the project, run npm install to install the Node modules.

The app is run with npm start. This does two things:

1. It compiles the TypeScript files into JavaScript.
2. It runs the compiled JavaScript code in the /dist directory.

The app prints on the console indicating the queried position on the coordinates, the coordinates of the link station with the strongest connection, and the power of that connection. Alternatively, if no link stations are within reach, it would indicate that instead.

The link stations have the following coordinates and reach levels:

• (0, 0), reach 10
• (20, 20), reach 5
• (10, 0), reach 12

The results are queried for devices in the following positions:

• (0,0)
• (100, 100)
• (15,10)
• (18, 18)

Documentation

Data Types

// Represents a position in the coordinates
type LatLng = [number, number]

// Link Station data object
interface LinkStation {
    position: LatLng
    reach: number
}

Formulas and Outputs

The application utilises two kinds of functions: formulas and outputs. Formulas handle the relationships of the data, thus substituting the server. The outputs handle the UI rendering logic, which conditionally log strings to the console.

Formulas

distance: function(a: LatLng, b: LatLng): number

Calculates the distance between point a and point b based on the Pythagorean Theorem.

getLinkStation: function(position: LatLng): LinkStation | null

Returns the link station with the optimal power available for the given position, or null if no link station is within reach.

calculatePower: function(linkStation: LinkStation, position: LatLng): number

Returns a number representing the power of connection between the given link station and the position. Always returns a positive number or zero.

Outputs

output: function(position: LatLng): void

Queries the optimal link station for the given position, and logs the result to the console.

There are two options:

In case there are link stations available:

"Best link station for point (x,y) is at point (x,y) with power z."

In case there are no link stations available:

"No link station within reach for point (x, y)."