Add Dijkstra in X86 64

[RMarx1456]

To request a new code snippet, please fill out the following:

Project name: Dijkstra
Project link: https://sampleprograms.io/projects/dijkstra/
Language: X86 64

The project link must be a link to a project on the [Sample Programs Website project list][sample-programs-project-list].
If you would like to add a new project to the Sample Programs Website,
please first make a pull request to the [Sample Programs Website][sample-programs-website].

[rzuckerm]

You are assign @RMarx1456