graph-bfs-dfs (in fact just a howto)

Author: parmentelat

notebooks/_toc.yml

@@ -24,6 +24,7 @@ parts:
   - file: howtos/encodings/HOWTO-encodings-nb
   - file: howtos/requests/HOWTO-requests-nb
   - file: howtos/adnwalk/HOWTO-adnwalk-nb
+  - glob: tps/graph-bfs-dfs/README*
   - file: howtos/subprocesses/HOWTO-subprocesses-nb
 - caption: TPs basiques
   chapters:
@@ -46,7 +47,6 @@ parts:
   - glob: tps/explang/README*
 - caption: TPs graphes
   chapters:
-  - glob: tps/graph-bfs-dfs/README*
   - glob: tps/graph-shortest-path/README*
   - file: tps/metro/README-metro-nb
   - glob: tps/pagerank-thrones/README*

notebooks/tps/graph-bfs-dfs/.teacher/README-graph-bfs-dfs-corrige-nb.md

@@ -14,7 +14,11 @@ language_info:
   pygments_lexer: ipython3
 ---
 
-# graph browsing
+# walking a graph: BFS - DFS
+
++++
+
+Licence CC BY-NC-ND, Thierry Parmentelat
 
 +++ {"tags": ["prune-cell"]}
 
@@ -26,9 +30,17 @@ there are no difference - apart from this very cell - between the teacher and th
 
 +++
 
-## depth-first or breadth-first scanning
+```{admonition} just a HOWTO
+:class: tip
+
+this notebook contains running code, there is no exercise attached
+```
+
++++
+
+## depth-first or breadth-first
 
-given a non-valued directed graph G, and a start vertex V, there are 2 famous algorithm to walk the graph from V
+given a non-valued directed graph G, and a start vertex V, there are 2 famous algorithms to walk the graph from V
 
 * depth-first (DF) browsing, and
 * breadth-first (BF) browsing
@@ -61,8 +73,9 @@ these 2 algorithms would yield the nodes in the following orders
 
 +++ {"cell_style": "split"}
 
-DF browsing **from `v`** would scan
-```
+DF browsing **from `v`** would scan (the newlines are only cosmetic)
+
+```text
 v v1 v11 v111 v112
 v12 v121 v122
 v2 v21 v211 v212
@@ -71,7 +84,7 @@ v22 v221 v222
 
 +++ {"cell_style": "split"}
 
-BF browsing **from `v`** would scan
+BF browsing **from `v`** would scan (ditto)
 ```
 v
 v1 v2
@@ -85,16 +98,14 @@ v111 v112 v121 v122 v211 v212 v221 v222
 
 +++
 
-we want to write a **generator** that implements these 2 browsing policies from a graph and vertex.
-
+we want to write a **generator** that implements these 2 browsing policies from a graph and vertex.  
 of course, only the nodes reachable from the entry vertex will be browsed by this method
 
 +++
 
 ## algorithms
 
-the 2 algorithms used to perform these scans are, interestingly, **very close** to one another
-
+the 2 algorithms used to perform these scans are, interestingly, **very close** to one another  
 in both cases we need a STORAGE object, where we can `store()` things and `retrieve()` them later on
 
 +++
@@ -108,9 +119,12 @@ Let us consider the following 2 storage implementations:
 * `Fifo` implements a *first-in-first-out* policy
 * `Filo` does the exact opposite and has a *first-in-last-out* policy
 
+```{admonition} list or deque
+
 Remember the regular `list` class is more optimized for a `append()/pop()` usage
 
 So to work around that, we're using a `deque` class, instead of a simple list; it is actually useful only in the `Filo` case, but this way we have a more homogeneous code
+```
 
 **Exercise**: you may wish to factorize both into a single class...