Create uniform cost search(UCS).py

Python/uniform cost search(UCS).py

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+from collections import defaultdict
+from queue import PriorityQueue
+
+
+class Graph:
+
+    def add_edge(self, u, v, weight):
+
+        value = (weight, v)
+        self.graph[u].append(value)
+        value = (weight, u)
+        self.graph[v].append(value)
+
+    def ucs(self, current_node, goal_node):
+        visited = []
+        queue = PriorityQueue()
+        queue.put((0, current_node))
+
+        while not queue.empty():
+            item = queue.get() # remove and returns a item in queue
+            current_node = item[1]
+
+            if current_node == goal_node:
+                print(current_node, end=" ")
+                queue.queue.clear()
+            else:
+                if current_node in visited:
+                    continue
+
+                print(current_node, end=" ")
+                visited.append(current_node) # added the visited current item by using .append()
+
+                for neighbour in self.graph[current_node]:
+                    queue.put((neighbour[0], neighbour[1]))
+
+
+g = Graph()
+g.graph = defaultdict(list)
+g.add_edge('A', 'B', 1)
+g.add_edge('A', 'C', 3)
+g.add_edge('B', 'G', 2)
+g.add_edge('B', 'F', 3)
+g.add_edge('C', 'G', 2)
+
+g.graph
+g.ucs('A', 'G')