add assignment F_graph_data

F_graph_data/README.md

+# Assignment F: Graph Data   (10 Pts)
+
+
+### Challenges
+- [Challenge 1:](#1-challenge-understanding-graph-data) Understanding Graph Data
+- [Challenge 2:](#2-challenge-representing-graph-data-in-python) Representing Graph Data in Python
+- [Challenge 3:](#3-challenge-implementing-the-graph-in-python) Implementing the Graph in Python
+- [Challenge 4:](#4-challenge-implementing-dijkstras-shortest-path-algorithm) Implementing Dijkstra's Shortest Path Algorithm
+- [Challenge 5:](#5-challenge-run-for-another-graph) Run for Another Graph
+
+Points: [1, 1, 2, 4, 2]
+
+
+ 
+### 1.) Challenge: Understanding Graph Data
+
+A *[Graph](https://en.wikipedia.org/wiki/Graph_theory)*
+is a set of nodes (vertices) and edges connecting nodes G = { n ∈ N, e ∈ E }.
+A *weighted Graph* has a *weight* (number) associated to each egde.
+
+A *[Path](https://en.wikipedia.org/wiki/Path_(graph_theory))*
+is a subset of edges that connects a subset of nodes.
+We consider Complete Graphs where all nodes can be reached from any other
+node by at least one path (no disconnected subgraphs).
+
+Graphs may have cycles (paths that lead to nodes visited before) or
+paths may join at nodes that are part of other paths.
+
+Traversal is the process of visiting each node of a graph exactly once.
+
+Multiple visits of graph nodes by cycles or joins must be detected by
+marking visited nodes (which is not preferred since it alters the data set)
+or by keeping a separate record of visits.
+
+Write two properties that distinguish graphs from trees.
+
+(1 Pt)
+
+
+ 
+### 2.) Challenge: Representing Graph Data in Python
+
+Python has no built-in data type that supports graph data.
+Separate packages my be used such as
+[NetworkX](https://networkx.org/).
+
+In this assignment, we focus on basic Python data structures.
+
+1. How can Graphs be represented in general?
+
+1. How can these by implemented using Python base data structures?
+
+1. Which data structure would be efficient giving the fact that in the
+    example below that graph is constant and only traversal operations
+    are performed?
+
+(1 Pt)
+
+
+ 
+### 3.) Challenge: Implementing the Graph in Python
+
+Watch the video and understand how
+[Dijkstra's Shortest Path Algorithm](https://en.wikipedia.org/wiki/Dijkstra%27s_algorithm)
+(1956) works and which information it needs.
+
+*Edsger W. Dijkstra* (1930-2003,
+[bio](https://en.wikipedia.org/wiki/Edsger_W._Dijkstra))
+was a Dutch computer scientist, programmer and software engineer.
+He was a professor of Computer Science at the Univerity of Austin, Texas
+and has received numerous awards, including the
+[Turing Award](https://en.wikipedia.org/wiki/Turing_Award)
+in 1972.
+
+<!--
+[video (FelixTechTips)](https://youtu.be/bZkzH5x0SKU?si=n8Z2ZIfbB73_v1TE)
+<img src="../markup/img/graph_2a.png" alt="drawing" width="640"/>
+-->
+[Video (Mike Pound, Computerphile)](https://youtu.be/GazC3A4OQTE?si=ZuBEcWaBzuKmPMqA)
+<img src="../markup/img/graph_1.png" alt="drawing" width="640"/>
+
+Node `S` forms the start of the algorithm, node `E` is the destination.
+
+Draw a sketch of the data structures needed to represent the graph with
+nodes, edges and weights and also the data needed for the algorithm.
+
+Create a Python file `shortest_path.py` with
+
+- declarations of data structures you may need for the graph and
+    information for the algorithm and
+
+- data to represent the graph in the video with nodes: {A ... K, S} and
+    the shown edges with weights.
+
+(2 Pts)
+
+
+&nbsp;
+### 4.) Challenge: Implementing Dijkstra's Shortest Path Algorithm
+
+Implement Dijkstra's Algorithm.
+
+Output the sortest path as sequence of nodes, followed by an analysis and
+the shortest distance.
+
+```
+shortest path: S -> B -> H -> G -> E
+analysis:
+S->B(2)
+B->H(1)
+H->G(2)
+G->E(2)
+shortest distance is: 7
+```
+(4 Pts)
+
+
+&nbsp;
+### 5.) Challenge: Run for Another Graph
+
+Run your algorithm for another graph G: {A ... F} with weights:
+```
+G: {A, B, C, D, E, F}, start: A, end: C
+
+Weights:
+AB(2), BE(6), EC(9), AD(8), BD(5),
+DE(3), DF(2), EF(1), FC(3)
+```
+
+Output the result:
+
+```
+shortest path: A -> B -> X -> F -> C
+analysis:
+S->B(2)
+B->D(5)
+D->F(2)
+F->C(3)
+shortest distance is: 12
+```
+(2 Pts)
+

README.md

@@ -8,6 +8,7 @@ This repository contains the assignments for class
 - Assignment C - [Python Expressions & Unit Tests](C_expressions).
 - Assignment D - [Recursive Problem Solving](D_recursion).
 - Assignment E - [Data Streams](E_streams).
+- Assignment F - [Graph Data](F_graph_data).