Added Breadth first search algorithm in graphs

Python/bfs.py

@@ -0,0 +1,51 @@
+class SimpleGraph:
+    def __init__(self):
+        self.edges = {}
+
+    def neighbors(self, id):
+        return self.edges[id]
+
+
+import collections
+
+class Queue:
+    def __init__(self):
+        self.elements = collections.deque()
+
+    def empty(self):
+        return len(self.elements) == 0
+
+    def put(self, x):
+        self.elements.append(x)
+
+    def get(self):
+        return self.elements.popleft()
+
+
+def breadth_first_search(graph, start):
+    # print out what we find
+    open_list = Queue()
+    open_list.put(start)
+    visited = {}
+    visited[start] = True
+
+    while not open_list.empty():
+        current = open_list.get()
+        print("Visiting %r" % current)
+        for next in graph.neighbors(current):
+            if next not in visited:
+                open_list.put(next)
+                visited[next] = True
+
+
+
+if __name__ == '__main__':
+	example_graph = SimpleGraph()
+	example_graph.edges = {
+    	'A': ['B'],
+    	'B': ['A', 'C', 'D'],
+    	'C': ['A'],
+    	'D': ['E', 'A'],
+    	'E': ['B']
+	}
+	breadth_first_search(example_graph, 'A')