StarMirror/interactive-coding-challenges
1
0
Fork 0
mirror of https://github.com/donnemartin/interactive-coding-challenges.git synced 2024-03-22 13:11:13 +08:00
Code Issues Projects Releases Wiki Activity

Update graph challenge (#117)

Browse Source 
Use more specific exception types. Update constraints. Update add_undirected_edge to use add_edge.
This commit is contained in:
Donne Martin 2016-11-13 07:32:33 -05:00 committed by GitHub
parent 3d4ae5c22f
commit 2d98b8a496
3 changed files with 31 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
graphs_trees/graph/graph.py
View File

@ -23,15 +23,17 @@ class Node:
return self.key < other.key
def add_neighbor(self, neighbor, weight=0):
if neighbor is None:
raise Exception('Invalid neighbor')
if neighbor is None or weight is None:
raise TypeError('neighbor or weight cannot be None')
neighbor.incoming_edges += 1
self.adj_weights[neighbor.key] = weight
self.adj_nodes[neighbor.key] = neighbor
def remove_neighbor(self, neighbor):
if neighbor is None or neighbor.key not in self.adj_nodes:
raise Exception('Invalid neighbor')
if neighbor is None:
raise TypeError('neighbor cannot be None')
if neighbor.key not in self.adj_nodes:
raise KeyError('neighbor not found')
neighbor.incoming_edges -= 1
del self.adj_weights[neighbor.key]
del self.adj_nodes[neighbor.key]
@ -44,7 +46,7 @@ class Graph:
def add_node(self, key):
if key is None:
raise Exception('Invalid key')
raise TypeError('key cannot be None')
if key in self.nodes:
return self.nodes[key]
self.nodes[key] = Node(key)
@ -60,9 +62,8 @@ class Graph:
self.nodes[source_key].add_neighbor(self.nodes[dest_key],
weight)
def add_undirected_edge(self, source_key, dest_key, weight=0):
if source_key is None or dest_key is None:
raise Exception('Invalid key')
self.add_edge(source_key, dest_key, weight)
self.nodes[dest_key].add_neighbor(self.nodes[source_key],
weight)
def add_undirected_edge(self, src_key, dst_key, weight=0):
if src_key is None or dst_key is None:
raise TypeError('key cannot be None')
self.add_edge(src_key, dst_key, weight)
self.add_edge(dst_key, src_key, weight)

4
graphs_trees/graph/graph_challenge.ipynb
View File

@ -38,12 +38,14 @@
" * Implement both\n",
"* Do the edges have weights?\n",
" * Yes\n",
"* Can we assume the inputs are valid?\n",
"* Can the graph have cycles?\n",
" * Yes\n",
"* If we try to add a node that already exists, do we just do nothing?\n",
" * Yes\n",
"* If we try to delete a node that doesn't exist, do we just do nothing?\n",
" * Yes\n",
"* Can we assume the inputs are valid?\n",
" * Yes\n",
"* Can we assume this fits memory?\n",
" * Yes"
]

27
graphs_trees/graph/graph_solution.ipynb
View File

@ -37,10 +37,14 @@
" * Implement both\n",
"* Do the edges have weights?\n",
" * Yes\n",
"* Can the graph have cycles?\n",
" * Yes\n",
"* If we try to add a node that already exists, do we just do nothing?\n",
" * Yes\n",
"* If we try to delete a node that doesn't exist, do we just do nothing?\n",
" * Yes\n",
"* Can we assume the inputs are valid?\n",
" * Yes\n",
"* Can we assume this fits memory?\n",
" * Yes"
]
@ -187,15 +191,17 @@
" return self.key < other.key\n",
"\n",
" def add_neighbor(self, neighbor, weight=0):\n",
" if neighbor is None:\n",
" raise Exception('Invalid neighbor')\n",
" if neighbor is None or weight is None:\n",
" raise TypeError('neighbor or weight cannot be None')\n",
" neighbor.incoming_edges += 1\n",
" self.adj_weights[neighbor.key] = weight\n",
" self.adj_nodes[neighbor.key] = neighbor\n",
"\n",
" def remove_neighbor(self, neighbor):\n",
" if neighbor is None or neighbor.key not in self.adj_nodes:\n",
" raise Exception('Invalid neighbor')\n",
" if neighbor is None:\n",
" raise TypeError('neighbor cannot be None')\n",
" if neighbor.key not in self.adj_nodes:\n",
" raise KeyError('neighbor not found')\n",
" neighbor.incoming_edges -= 1\n",
" del self.adj_weights[neighbor.key]\n",
" del self.adj_nodes[neighbor.key]\n",
@ -208,7 +214,7 @@
"\n",
" def add_node(self, key):\n",
" if key is None:\n",
" raise Exception('Invalid key')\n",
" raise TypeError('key cannot be None')\n",
" if key in self.nodes:\n",
" return self.nodes[key]\n",
" self.nodes[key] = Node(key)\n",
@ -224,12 +230,11 @@
" self.nodes[source_key].add_neighbor(self.nodes[dest_key],\n",
" weight)\n",
"\n",
" def add_undirected_edge(self, source_key, dest_key, weight=0):\n",
" if source_key is None or dest_key is None:\n",
" raise Exception('Invalid key')\n",
" self.add_edge(source_key, dest_key, weight)\n",
" self.nodes[dest_key].add_neighbor(self.nodes[source_key],\n",
" weight)"
" def add_undirected_edge(self, src_key, dst_key, weight=0):\n",
" if src_key is None or dst_key is None:\n",
" raise TypeError('key cannot be None')\n",
" self.add_edge(src_key, dst_key, weight)\n",
" self.add_edge(dst_key, src_key, weight)"
]
},
{