Graph-Search: Initial scaffolding

Graph-Search/README.md

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+# Lab 11: Graph Search - Bus Stops
+
+## Graph Search Basics
+
+The purpose of this lab is to give you practice implementing graph data
+structures and basic graph traversal and reachability queries.
+
+You are building an app for a newly created bus system connecting Harrisonburg
+to Charlottesville. There are many different bus routes each of which travels
+between named stops along its route. Not all of the bus routes cross each other,
+so it is possible that there are some pairs of stops where there is no way of
+getting on a bus at the first stop and making changes to get to the final stop.
+Your task is to implement a graph search function that can determine a sequence
+of stops a user can use to get from a starting stop to an ending stop, or to
+tell the user that there is no bus route possible between those two stops.
+
+## Input
+
+The bus route segments are described as single stretches of road between two
+consecutive stops. All such pairs will be described in one direction, but all
+bus routes are bidirectional, since buses travel in both directions along each
+route.
+
+The first line of input has an integer n that is the number of road segments
+between consecutive stops. The next n lines of input describe the consecutive
+stops, each of which is named by a string of alphabetical characters with no
+spaces. The line will contain both of the stops of the segment, separated by a
+space.
+
+The final line of input is the query, which is two stop names separated by a
+space.
+
+## Output
+
+Give a sequence of stop names starting at the starting stop of the query and
+ending at the ending stop separated by spaces (if one exists), or output "no
+route possible" if none is found.
+
+<table>
+    <tr>
+        <td>Sample Input</td>
+        <td>Sample Output</td>
+    </tr>
+    <tr>
+        <td><pre>
+2
+Hburg JMU
+Charlottesville JMU
+Hburg Charlottesville</pre></td>
+        <td><pre>Hburg JMU Charlottesville</pre></td>
+    </tr>
+    <tr>
+        <td><pre>
+4
+Hburg JMU
+JMU Upark
+Upark Hburg
+CVO UVA
+Hburg UVA</pre></td>
+        <td><pre>no route possible</pre></td>
+    </tr>
+</table>
+
+Larger example files (the one used on Gradescope) can be downloaded here:
+bus_stops_t3_in.txt Download bus_stops_t3_in.txt bus_stops_t3_exp.txt Download
+bus_stops_t3_exp.txt Depending how you implement your graph, the order of stops
+on the path may not be unique, so, checking your solution requires writing a bit
+more code to validate your path (and of course, that is optional).
+
+## Hints:
+
+- Store the stops in a dictionary and use a set for the edge list.
+- You will need to implement a method that uses a spanning tree. The lab is
+  asking you for a path between the locations (not necessarily the shortest
+  path).
+
+## Submission:
+
+Your code in a file name `cs412_bus_stops_a.py` and submit your code to
+gradescope.
+
+## Rubrics:
+
+- (6 points) program solves the examples
+- (3 points) solves the hidden examples
+- (1 point) instructor review

Graph-Search/cs412_bus_stops_a.py

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+"""
+name: Nicholas Tamassia
+
+Honor Code and Acknowledgments:
+
+        This work complies with the JMU Honor Code.
+
+       Comments here on your code and submission.
+"""
+
+from collections import deque
+
+
+def whatever_first_search(
+    graph: dict[str, set[str]], start: str, stop: str
+) -> list[str]:
+
+    return []
+
+
+# All modules for CS 412 must include a main method that allows it
+# to imported and invoked from other python scripts
+def main():
+    n: int = int(input())
+
+    graph: dict[str, set[str]] = {}
+
+    for _ in range(0, n):
+        u, v = input().split()
+
+        if u not in graph:
+            graph[u] = set([v])
+        else:
+            graph[u].add(v)
+
+    target = input().split()
+
+    path = whatever_first_search(graph, target[0], target[1])
+
+    if len(path) == 0:
+        print("no route possible")
+    else:
+        print(" ".join(path))
+
+
+if __name__ == "__main__":
+    main()

Graph-Search/inputs/sample1.txt

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+2
+Hburg JMU
+Charlottesville JMU
+Hburg Charlottesville

Graph-Search/inputs/sample2.txt

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+4
+Hburg JMU
+JMU Upark
+Upark Hburg
+CVO UVA
+Hburg UVA