Description

This repository is an implementation of the task of generating playlists. There is a set of ~ 5k songs from which you need to make playlists. The playlist consists of songs, where each song (except the first) begins with the same letter as the previous song ends. The application should process requests from users to create a playlist of length K (the first song is selected randomly).

The problem described above is reduced to the problem of finding the longest path in a directed graph. Since the graph based on the provided list of songs contains cycles, the problem does not have a polynomial solution. Therefore, the problem was solved using k-SGL heuristics, given in master's work (pages 29-33), as the most effective for the structure of the resulting directed graph.

After deploying this application, API endpoint will be available for the HTTP-request to create a playlist of K songs. An example of request and response is shown below:

curl -X GET 'http://localhost:5000/playlists?length=5'

{
    "songs": [
        {
            "id": 3574,
            "artist": "Depeche Mode",
            "original_name": "People Are People",
            "name": "people are people",
            "duration": 232176
        },
        {
            "id": 4769,
            "artist": "Johnny Cash & Waylon Jennings",
            "original_name": "Even Cowgirls Get the Blues",
            "name": "even cowgirls get the blues",
            "duration": 183040
        },
        {
            "id": 5106,
            "artist": "Loreena McKennitt",
            "original_name": "Standing Stones",
            "name": "standing stones",
            "duration": 419186
        },
        {
            "id": 5046,
            "artist": "Liz Story",
            "original_name": "Solid Colors",
            "name": "solid colors",
            "duration": 278709
        },
        {
            "id": 5018,
            "artist": "Attaboy",
            "original_name": "Solid Space Business",
            "name": "solid space business",
            "duration": 132937
        }
    ],
    "length": 5,
    "duration": 1246048
}

Installation

npm install

Development

npm run serve:dev // start in development mode
npm run test      // run unit tests
npm run lint      // check code quality

Production

npm run start