Mario on a mission

Mario and the princess are trapped in a square grid (N*N), Mario needs to reach the princess with a minimum number of steps (shortest paths), while avoiding any obstacles. Mario can move UP, DOWN, LEFT and RIGHT and can’t go outside of the grid.

First task:

1. Validate the given inputs
   • max 1 Mario and 1 princess.
   • minimum 1 Mario and 1 princess.
   • Grid should form a square matrix.
   • the given integer 'n' should be a positive number greater than 1
2. Find the shortest path to reach princess avoiding all the obstacles.
3. If you don't find the shortest path, then return any possible path if it exists.

• Inputs:

  n: grid size,

    For example 3
  

  grid: n*n matrix in the form of string. Each row is separated by a comma.

    For example: '--m,-x-,-p-'
  

• Output:

    (ERROR_FLAG, [PATH])
  

  For example,

    (True, []) - if any of the constraints are violated. Here True is the
    (False, []) - if all paths to princess are blocked by obstacles
    (False, ['DOWN', 'DOWN', 'LEFT']) - if we find the shortest path or a possible path to the princess
  

• How to use:

  Simply run input.py from app/save_princess package and provide inputs.

Second task

how to run:

• goto a directory where main.py is present.
• run set FLASK_APP=main.py if you are on windows other export FLASK_APP=main.py
• flask db upgrade
• Finally, start the flask application by running - flask run

I'm exposing 3 Rest API endpoints.

• First is to find the shortest path. This uses the algorithm writer in task1.
• Second is to see the request logs for a particular request.
• The third is to see all the request logs.

Additionally, I'm using SQLLite DB to store the requests.

The clients of these API's can use them in the following manner

• shortest path or Possible path if any

  URL:

    /api/v1/mario/n/grid
  

  Method:

    GET
  

  URL Params:

    Required: n = [integer]
              grid = [alphanumeric]
  

  Successful Responses:

  • URL(Shortest Path):

      api/v1/mario/3/--m,-x-,-p-
    
      {
          "error_flag": false,
          "paths": [
              "DOWN",
              "DOWN",
              "LEFT"
          ]
      }
    

  • URL(Possible Path):

      api/v1/mario/5/m--x-,xx--x,-----,-xxxx,----p
    
      {
          "error_flag": false,
          "paths": [
          "RIGHT",
          "RIGHT",
          "DOWN",
          "DOWN",
          "LEFT",
          "LEFT",
          "DOWN",
          "DOWN",
          "RIGHT",
          "RIGHT",
          "RIGHT",
          "RIGHT"
          ]
      }
    

  • URL(No Possible Path):

      api/v1/mario/5/m--x-,xx--x,-----,xxxxx,----p
    
      {
          "error_flag": false,
          "paths": []
      }
    

  Error Response:

  • URL:

      api/v1/mario/5/m--x-,xx--x,-----
    
      {
          "error_flag": true,
          "paths": []
      }
    

• Request log data.

  URL:

    /api/v1/mario/logs 
    /api/v1/mario/logs/id
  

  Method:

    GET
  

  URL Params:

    Optional: id = [integer]
  

  Successful Response:

    Examlple: /api/v1/mario/logs
  
    [
        {
            "id": 6,
            "remote_address": "127.0.0.1",
            "n": 3,
            "url": "http://host:5000/api/v1/mario/3/--m%2Cxxx%2C--p",
            "grid": "--m,-x-,--p",
            "timestamp": "2019-09-19T13:26:09.328501"
        },
        {
            "id": 7,
            "remote_address": "127.0.0.1",
            "n": 3,
            "url": "http://host:5000/api/v1/mario/3/--m%2Cxxx%2C--p",
            "grid": "--m,xxx,p-p",
            "timestamp": "2019-09-19T16:41:10.107362"
        }
    ]
    
    Examlple: /api/v1/mario/logs/6
    
    {
        "id": 6,
        "remote_address": "127.0.0.1",
        "n": 3,
        "url": "http://localhost:5000/api/v1/mario/3/--m%2Cxxx%2C--p",
        "grid": "--m,xxx,--p",
        "timestamp": "2019-09-19T13:26:09.328501"
    }
  

Third Task

Task: Create a web application to play the Mario game created in task one.

To make the web application interactive I have used Dash by Plotly and added error messages if the inputs are invalid.

The user can just go to /dashboard/ to play the game. Let's start then

If the User enters a valid input and there are no obstacles on the shortest path. The screen will look something like this

If the User enters a valid input but there are obstacles on the shortest path. Then the game will find the possible path. The screen will look something like this

If the User enters a valid input but there are obstacles everywhere. The screen will look something like this.

If the user enters invalid grid

If the number of Mario is more than 1