Shortest Path Algorithm (Part 1)

Drawing an empty board to visualize the execution of shortest path algorithms.

Tiago Temporin
Aug 5, 2020 · 2 min read

This is the first part of a study on how shortest path algorithms work. This study is divided into three parts.

  • 1) Draw an empty board
  • 2) Add obstacles randomly
  • 3) Implement the shortest path algorithm

# 1 - Dependencies

pip install Pillow

# 2 - Imports

from PIL import Image, ImageDraw

*PIL is short for Python Image Library

# 3 - Classes

The Node class will hold each position of the board.

Inside the draw method, we use the ImageDraw class to create the image of the node.

The most important part is the first parameter of the rectangle method. This parameter is responsible for the positions of the pixels that the class will use to draw our node.

The shape is an array with two positions. In the first position, we define where is the top/left edge of the rectangle and in the second, the bottom/right edge.

With these definitions, the method will draw:

  • One vertical line from the left/top edge to the relative left/bottom edge;
  • One vertical line from the right/bottom edge to the relative right/top edge;
  • One horizontal line from the left/top edge to the relative right/top edge;
  • One horizontal line from the right/bottom edge to the relative left/bottom edge.

In the end, we have a rectangle.

Now we need to create the Board class, to hold the matrix of Nodes, and draw the final image.

# 4 - Drawing

This is it! See you in the next part!

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Tiago Temporin

Written by

Angular and Go programmer. Open Source lover ❤!

The Startup

Get smarter at building your thing. Follow to join The Startup’s +8 million monthly readers & +794K followers.

Tiago Temporin

Written by

Angular and Go programmer. Open Source lover ❤!

The Startup

Get smarter at building your thing. Follow to join The Startup’s +8 million monthly readers & +794K followers.

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