slightly better graphs

DavidLeoni · Dec 12, 2019 · b6c912a · b6c912a
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diff --git a/exercises/graph-algos/graph-algos.ipynb b/exercises/graph-algos/graph-algos.ipynb
diff --git a/exercises/graph-algos/graph_solution.py b/exercises/graph-algos/graph_solution.py
@@ -241,14 +241,18 @@ def remove_vertex(self, vertex):
     def transpose(self):
         """ Reverses the direction of all the edges 
         
+            - MUST perform in O(|V|+|E|)  
+                 Note in adjacency lists model we suppose there are only few edges per node,
+                 so if you end up with an algorithm which is O(|V|^2) you are ending up with a
+                 complexity usually reserved for matrix representations !!
+
             NOTE: this method changes in-place the graph: does **not** create a new instance
-            and does *not* return anything !!
+                  and does *not* return anything !!
             
             NOTE: To implement it *avoid* modifying the existing _edges dictionary (would
-            probably more problems than anything else).
-            Instead, create a new dictionary, fill it with the required 
-            verteces and edges ad then set _edges to point to the new dictionary.
-
+                  probably more problems than anything else).
+                  Instead, create a new dictionary, fill it with the required 
+                  verteces and edges ad then set _edges to point to the new dictionary.
         """
         #jupman-raise
 

diff --git a/index.ipynb b/index.ipynb
@@ -466,72 +466,6 @@
     "\n",
     "7 November 2019: published [Midterm Part A solution](exams/2019-11-07/exam-2019-11-07-solution.ipynb) \n",
     "\n",
-    "5 November 2019: **WARNING: TUTORING CHANGE**\n",
-    "\n",
-    "Since Fridays apparently aren't the best day for tutoring (nobody went twice in a row), **we're moving Friday tutoring to Wednesday 9:00-11:00 starting with Wednesday 6 November. Rooms: A219 until Wednesday 13 November included, A218 afterwards**\n",
-    "\n",
-    "Given the fact many of you took ages to do the midterm simulation, I'd recommend attendance.\n",
-    "\n",
-    "2 November 2019:\n",
-    "\n",
-    "- published [Midterm simulation solutions](exams/2019-10-31/exam-2019-10-31-solution.ipynb) \n",
-    "- added NaN and infinities section to [matrix: numpy exercises](exercises/matrices-numpy/matrices-numpy-solution.ipynb)\n",
-    "- improved [pandas exercises](exercises/pandas/pandas-solution.ipynb)\n",
-    "- added [functions exercises](exercises/functions/functions-solution.ipynb)\n",
-    "\n",
-    "24 October 2019: updated [numpy matrices](exercises/matrices-numpy/matrices-numpy-solution.ipynb) and [visualization](exercises/visualization/visualization-solution.ipynb) \n",
-    "\n",
-    "22 October 2019: WARNING: TUTORING TIMETABLE CHANGE! \n",
-    "\n",
-    "Unfortunately, due to reasons beyond our control we need need to change timetable for tutoring:\n",
-    "\n",
-    "- Mondays remain the same:   room A215 from 11.30-13.30\n",
-    "\n",
-    "- Fridays change:   instead of previous 12.30-14:30,   the new hours will be 11.00-13.00. Friday room is also changed, it will be A218 for all fridays\n",
-    "\n",
-    "\n",
-    "- Graph formats draw functions:\n",
-    "    - fixed bug about username not found in windows\n",
-    "    - now it is possible to save to file in draw_mat, draw_nx, etc by passing filename in parameter `save_to`, [see documentation](https://datasciprolab.readthedocs.io/en/latest/exercises/graph-formats/graph-formats-solution.html#Saving-a-graph-to-a-file)\n",
-    "\n",
-    "17 October 2019 : rewrote [Graph formats](exercises/graph-formats/graph-formats-solution.ipynb) page\n",
-    "\n",
-    "12 October 2019 : tutoring service has been set up on Mondays and Fridays starting Monday 14th October, see [timetable](#Tutoring)\n",
-    "\n",
-    "\n",
-    "10 October 2019: Save the dates:\n",
-    "\n",
-    "- MIDTERM PART A SIMULATION: 31 october 15:30-17:30 room a202\n",
-    "\n",
-    "- MIDTERM PART A: 7 november 11:30-13:30 room b106 \n",
-    "\n",
-    "IMPORTANT: differently from past Part A exams, there will also be an exercise on Pandas.\n",
-    "\n",
-    "- merged Part A graph stuff into [graph formats](https://datasciprolab.readthedocs.io/en/latest/exercises/graph-formats/graph-formats-solution.html)\n",
-    "\n",
-    "7 October 2019\n",
-    "\n",
-    "- added [Tuples](exercises/tuples/tuples-solution.ipynb) page (were extracted from [Lists](exercises/lists/lists-solution.ipynb))\n",
-    "- updated [Dictionaries](exercises/dictionaries/dictionaries-solution.ipynb)\n",
-    "- rewrote [Sets](exercises/sets/sets-solution.ipynb), now belongs to Part A\n",
-    "\n",
-    "3 October 2019: updated [Lists](exercises/lists/lists-solution.ipynb)\n",
-    "\n",
-    "1 October 2019\n",
-    "\n",
-    "- updated [Strings](exercises/strings/strings-solution.ipynb)\n",
-    "- updated  [error handling and testing](exercises/errors-and-testing/errors-and-testing-solution.ipynb)    \n",
-    "\n",
-    "24 September 2019\n",
-    "\n",
-    "- updated  [introduction](exercises/introduction/introduction-solution.ipynb)\n",
-    "- added [Python basics](exercises/basics/basics-solution.ipynb)\n",
-    "\n",
-    "27 August 2019: published  [exam solutions](exams/2019-08-26/exam-2019-08-26-solution.ipynb)\n",
-    "\n",
-    "2 July 2019: published  [exam solutions](exams/2019-07-02/exam-2019-07-02-solution.ipynb)\n",
-    "\n",
-    "10 June 2019: published  [exam solutions](exams/2019-06-10/exam-2019-06-10-solution.ipynb)\n",
     "\n",
     "[Old news](old-news.ipynb)"
    ]
@@ -813,7 +747,9 @@
     "\n",
     "* Part B theory slides by Luca Bianco\n",
     "\n",
-    "* [Problem Solving with Algorithms and Data Structures using Python](https://runestone.academy/runestone/static/pythonds/index.html) online book by Brad Miller and David Ranum\n"
+    "* [Problem Solving with Algorithms and Data Structures using Python](https://runestone.academy/runestone/static/pythonds/index.html) online book by Brad Miller and David Ranum\n",
+    "\n",
+    "* [Theory exercises (complexity, tree visits, graph visits) - by Alberto Montresor](https://drive.google.com/drive/folders/1RwjiSvIq60Z9mj_gCd5K2E6Bj9y1R0CL)"
    ]
   },
   {
@@ -883,7 +819,7 @@
    "toc_cell": false,
    "toc_position": {},
    "toc_section_display": true,
-   "toc_window_display": false
+   "toc_window_display": true
   }
  },
  "nbformat": 4,

diff --git a/old-news.ipynb b/old-news.ipynb
@@ -426,6 +426,73 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
+    "5 November 2019: WARNING: TUTORING CHANGE\n",
+    "\n",
+    "Since Fridays apparently aren't the best day for tutoring (nobody went twice in a row), we're moving Friday tutoring to Wednesday 9:00-11:00 starting with Wednesday 6 November. Rooms: A219 until Wednesday 13 November included, A218 afterwards\n",
+    "\n",
+    "Given the fact many of you took ages to do the midterm simulation, I'd recommend attendance.\n",
+    "\n",
+    "2 November 2019:\n",
+    "\n",
+    "- published [Midterm simulation solutions](exams/2019-10-31/exam-2019-10-31-solution.ipynb) \n",
+    "- added NaN and infinities section to [matrix: numpy exercises](exercises/matrices-numpy/matrices-numpy-solution.ipynb)\n",
+    "- improved [pandas exercises](exercises/pandas/pandas-solution.ipynb)\n",
+    "- added [functions exercises](exercises/functions/functions-solution.ipynb)\n",
+    "\n",
+    "24 October 2019: updated [numpy matrices](exercises/matrices-numpy/matrices-numpy-solution.ipynb) and [visualization](exercises/visualization/visualization-solution.ipynb) \n",
+    "\n",
+    "22 October 2019: WARNING: TUTORING TIMETABLE CHANGE! \n",
+    "\n",
+    "Unfortunately, due to reasons beyond our control we need need to change timetable for tutoring:\n",
+    "\n",
+    "- Mondays remain the same:   room A215 from 11.30-13.30\n",
+    "\n",
+    "- Fridays change:   instead of previous 12.30-14:30,   the new hours will be 11.00-13.00. Friday room is also changed, it will be A218 for all fridays\n",
+    "\n",
+    "\n",
+    "- Graph formats draw functions:\n",
+    "    - fixed bug about username not found in windows\n",
+    "    - now it is possible to save to file in draw_mat, draw_nx, etc by passing filename in parameter `save_to`, [see documentation](https://datasciprolab.readthedocs.io/en/latest/exercises/graph-formats/graph-formats-solution.html#Saving-a-graph-to-a-file)\n",
+    "\n",
+    "17 October 2019 : rewrote [Graph formats](exercises/graph-formats/graph-formats-solution.ipynb) page\n",
+    "\n",
+    "12 October 2019 : tutoring service has been set up on Mondays and Fridays starting Monday 14th October, see [timetable](#Tutoring)\n",
+    "\n",
+    "\n",
+    "10 October 2019: Save the dates:\n",
+    "\n",
+    "- MIDTERM PART A SIMULATION: 31 october 15:30-17:30 room a202\n",
+    "\n",
+    "- MIDTERM PART A: 7 november 11:30-13:30 room b106 \n",
+    "\n",
+    "IMPORTANT: differently from past Part A exams, there will also be an exercise on Pandas.\n",
+    "\n",
+    "- merged Part A graph stuff into [graph formats](https://datasciprolab.readthedocs.io/en/latest/exercises/graph-formats/graph-formats-solution.html)\n",
+    "\n",
+    "7 October 2019\n",
+    "\n",
+    "- added [Tuples](exercises/tuples/tuples-solution.ipynb) page (were extracted from [Lists](exercises/lists/lists-solution.ipynb))\n",
+    "- updated [Dictionaries](exercises/dictionaries/dictionaries-solution.ipynb)\n",
+    "- rewrote [Sets](exercises/sets/sets-solution.ipynb), now belongs to Part A\n",
+    "\n",
+    "3 October 2019: updated [Lists](exercises/lists/lists-solution.ipynb)\n",
+    "\n",
+    "1 October 2019\n",
+    "\n",
+    "- updated [Strings](exercises/strings/strings-solution.ipynb)\n",
+    "- updated  [error handling and testing](exercises/errors-and-testing/errors-and-testing-solution.ipynb)    \n",
+    "\n",
+    "24 September 2019\n",
+    "\n",
+    "- updated  [introduction](exercises/introduction/introduction-solution.ipynb)\n",
+    "- added [Python basics](exercises/basics/basics-solution.ipynb)\n",
+    "\n",
+    "27 August 2019: published  [exam solutions](exams/2019-08-26/exam-2019-08-26-solution.ipynb)\n",
+    "\n",
+    "2 July 2019: published  [exam solutions](exams/2019-07-02/exam-2019-07-02-solution.ipynb)\n",
+    "\n",
+    "10 June 2019: published  [exam solutions](exams/2019-06-10/exam-2019-06-10-solution.ipynb)\n",
+    "\n",
     "- 13 January 2019: published  [exam solutions](exams/2019-02-13/exam-2019-02-13-solution.ipynb)\n",
     "- 23 January 2019: published [exam solutions](exams/2019-01-23/exam-2019-01-23-solution.ipynb)\n",
     "- 23 January 2019: removed children() method from GenericTree (you shouldn't use it anyway)\n",
@@ -497,7 +564,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.5.2"
+   "version": "3.7.3"
   },
   "toc": {
    "base_numbering": 1,

diff --git a/slides.ipynb b/slides.ipynb
@@ -471,6 +471,22 @@
     "At home: finish generic trees section"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Lab B.10\n",
+    "\n",
+    "Thursday 12 December\n",
+    "\n",
+    "* [Graphs](exercises/graphs/graphs.ipynb) \n",
+    "\n",
+    "    1. [Implement building](/exercises/graph-algos/graph-algos.html#1.-Implement-building)\n",
+    "    2. [Manipulate graphs](/exercises/graph-algos/graph-algos.html#2.-Manipulate-graphs)\n",
+    "\n",
+    "At home: finish Section 1 and 2"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,