daknuett/scientific-programming-exercises
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fixed one bug in dijkstra backtracking

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This commit is contained in:
Daniel Knuettel 2019-02-27 11:41:44 +01:00
parent a7539c1cad
commit 9ba52e80f1
4 changed files with 10 additions and 7 deletions
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2
exam/ex01/cfg.py
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@ -1,6 +1,6 @@
config = {
"use_sqlite": False
"use_sqlite": True
, "mysql_server": "172.17.0.2"
, "mysql_user": "wikipedia"
, "mysql_password": "wikipediastuff"

5
exam/ex01/graph.py
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@ -27,7 +27,8 @@ class DijkstraHelper(object):
return cls(nodes, connections)
def dijkstra(self, root):
self.recursive_dijkstra([root], 0)
self._nodes[root] = 0
self.recursive_dijkstra([root], 1)
def recursive_dijkstra(self, todos, depth):
if(not todos):
@ -58,4 +59,4 @@ class DijkstraHelper(object):
cursor.executemany(sql.statements["insert_dijkstra_values"], [(k, sqlize(v)) for k,v in self._nodes.items()])
connection.commit()

8
exam/ex01/main.py
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@ -9,7 +9,7 @@ from dijkstra import prepare_dijkstra, dijkstra
from connectivity import shortest_path
from graph import DijkstraHelper
from db_util import get_page_id
from db_util import get_page_id, get_page_title
cache = get_cache("./cache/", "Angela_Merkel")
receive_link_graph("Angela_Merkel", cache, 2)
@ -21,7 +21,6 @@ print(cursor.fetchall())
#prepare_dijkstra(cache)
#dijkstra("Angela_Merkel", cache)
#
#print(shortest_path("Angela_Merkel", "Germany", cache))
angela = get_page_id("Angela_Merkel", cache)
@ -29,4 +28,7 @@ angela = get_page_id("Angela_Merkel", cache)
dijkstra = DijkstraHelper.from_db(cache)
dijkstra.dijkstra(angela)
dijkstra.write_back(cache)
print({k:v for k,v in dijkstra._nodes.items() if v != float("inf")})
#print({k:v for k,v in dijkstra._nodes.items() if v != float("inf")})
print([get_page_title(id_, cache) for id_ in shortest_path("Angela_Merkel", "Germany", cache)])
print([get_page_title(id_, cache) for id_ in shortest_path("Angela_Merkel", "2012_Nobel_Peace_Prize", cache)])

2
exam/ex01/sql.py
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@ -29,7 +29,7 @@ sql_statements = {
, "mysql": "SELECT COUNT(destination) FROM links WHERE destination=%s"}
, "dijkstra_backtrack_one": {"sqlite": '''SELECT links.source
FROM links
LEFT JOIN dijkstra_helper ON links.destination=dijkstra_helper.page
LEFT JOIN dijkstra_helper ON links.source=dijkstra_helper.page
WHERE links.destination=?
ORDER BY dijkstra_helper.value ASC
LIMIT 1'''