From 51192870300b45076276dc285b94125a6d25175f Mon Sep 17 00:00:00 2001
From: Lewis Tian <taseikyo@gmail.com>
Date: Fri, 20 Nov 2020 15:09:54 +0800
Subject: [PATCH 1/2] update graphs/breadth_first_search.py

- update naming style to snake_case
- add type hints
---
 graphs/breadth_first_search.py | 38 ++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/graphs/breadth_first_search.py b/graphs/breadth_first_search.py
index e40ec9d1d06d..14ecfe0ee8d5 100644
--- a/graphs/breadth_first_search.py
+++ b/graphs/breadth_first_search.py
@@ -2,24 +2,26 @@
 
 """ Author: OMKAR PATHAK """
 
+from typing import Set
+
 
 class Graph:
     def __init__(self):
         self.vertices = {}
 
-    def printGraph(self):
+    def print_graph(self) -> None:
         """prints adjacency list representation of graaph"""
-        for i in self.vertices.keys():
+        for i in self.vertices:
             print(i, " : ", " -> ".join([str(j) for j in self.vertices[i]]))
 
-    def addEdge(self, fromVertex, toVertex):
+    def add_edge(self, from_vertex: int, to_vertex: int) -> None:
         """adding the edge between two vertices"""
-        if fromVertex in self.vertices.keys():
-            self.vertices[fromVertex].append(toVertex)
+        if from_vertex in self.vertices:
+            self.vertices[from_vertex].append(to_vertex)
         else:
-            self.vertices[fromVertex] = [toVertex]
+            self.vertices[from_vertex] = [to_vertex]
 
-    def BFS(self, startVertex):
+    def bfs(self, start_vertex: int) -> Set[int]:
         # initialize set for storing already visited vertices
         visited = set()
 
@@ -27,8 +29,8 @@ def BFS(self, startVertex):
         queue = []
 
         # mark the source node as visited and enqueue it
-        visited.add(startVertex)
-        queue.append(startVertex)
+        visited.add(start_vertex)
+        queue.append(start_vertex)
 
         while queue:
             vertex = queue.pop(0)
@@ -43,17 +45,17 @@ def BFS(self, startVertex):
 
 if __name__ == "__main__":
     g = Graph()
-    g.addEdge(0, 1)
-    g.addEdge(0, 2)
-    g.addEdge(1, 2)
-    g.addEdge(2, 0)
-    g.addEdge(2, 3)
-    g.addEdge(3, 3)
-
-    g.printGraph()
+    g.add_edge(0, 1)
+    g.add_edge(0, 2)
+    g.add_edge(1, 2)
+    g.add_edge(2, 0)
+    g.add_edge(2, 3)
+    g.add_edge(3, 3)
+
+    g.print_graph()
     # 0  :  1 -> 2
     # 1  :  2
     # 2  :  0 -> 3
     # 3  :  3
 
-    assert sorted(g.BFS(2)) == [0, 1, 2, 3]
+    assert sorted(g.bfs(2)) == [0, 1, 2, 3]

From 0b36986b9fd62f6617e376934b6bc45850bb7549 Mon Sep 17 00:00:00 2001
From: Lewis Tian <taseikyo@gmail.com>
Date: Fri, 20 Nov 2020 15:46:48 +0800
Subject: [PATCH 2/2] add doctests

---
 graphs/breadth_first_search.py | 36 +++++++++++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/graphs/breadth_first_search.py b/graphs/breadth_first_search.py
index 14ecfe0ee8d5..ee9855bd0c2d 100644
--- a/graphs/breadth_first_search.py
+++ b/graphs/breadth_first_search.py
@@ -6,22 +6,48 @@
 
 
 class Graph:
-    def __init__(self):
+    def __init__(self) -> None:
         self.vertices = {}
 
     def print_graph(self) -> None:
-        """prints adjacency list representation of graaph"""
+        """
+        prints adjacency list representation of graaph
+        >>> g = Graph()
+        >>> g.print_graph()
+        >>> g.add_edge(0, 1)
+        >>> g.print_graph()
+        0  :  1
+        """
         for i in self.vertices:
             print(i, " : ", " -> ".join([str(j) for j in self.vertices[i]]))
 
     def add_edge(self, from_vertex: int, to_vertex: int) -> None:
-        """adding the edge between two vertices"""
+        """
+        adding the edge between two vertices
+        >>> g = Graph()
+        >>> g.print_graph()
+        >>> g.add_edge(0, 1)
+        >>> g.print_graph()
+        0  :  1
+        """
         if from_vertex in self.vertices:
             self.vertices[from_vertex].append(to_vertex)
         else:
             self.vertices[from_vertex] = [to_vertex]
 
     def bfs(self, start_vertex: int) -> Set[int]:
+        """
+        >>> g = Graph()
+        >>> g.add_edge(0, 1)
+        >>> g.add_edge(0, 1)
+        >>> g.add_edge(0, 2)
+        >>> g.add_edge(1, 2)
+        >>> g.add_edge(2, 0)
+        >>> g.add_edge(2, 3)
+        >>> g.add_edge(3, 3)
+        >>> sorted(g.bfs(2))
+        [0, 1, 2, 3]
+        """
         # initialize set for storing already visited vertices
         visited = set()
 
@@ -44,6 +70,10 @@ def bfs(self, start_vertex: int) -> Set[int]:
 
 
 if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod(verbose=True)
+
     g = Graph()
     g.add_edge(0, 1)
     g.add_edge(0, 2)