added dijkstra algo.

tutorials/Graph World/dijkstra.py

@@ -0,0 +1,109 @@
+from traverseCraft.world import CreateGraphWorld
+from traverseCraft.agent import GraphAgent
+import heapq
+from prettytable import PrettyTable
+
+def dijkstra(startNode, world, agent):
+    # Initialize distances with infinity and set start node distance to 0
+    distances = {node: float('inf') for node in world.nodeMap.keys()}
+    previous_nodes = {node: None for node in world.nodeMap.keys()}
+    distances[startNode] = 0
+    priority_queue = [(0, startNode)]
+
+    while priority_queue:
+        current_distance, current_node = heapq.heappop(priority_queue)
+        # If the current distance is greater than the recorded distance, skip it
+        if current_distance > distances[current_node]:
+            continue
+
+        agent.moveAgent(current_node, delay=0.3)
+
+        curr_node = world.nodeMap[current_node]
+
+        for neighbor, weight in zip(curr_node.neighbors, curr_node.edges):
+            distance = current_distance + weight
+
+            # Only consider this new path if it's better
+            if distance < distances[neighbor.id]:
+                distances[neighbor.id] = distance
+                previous_nodes[neighbor.id] = current_node
+                heapq.heappush(priority_queue, (distance, neighbor.id))
+
+    return distances, previous_nodes
+
+def get_path(previous_nodes, startNode, targetNode):
+    path = []
+    current_node = targetNode
+    while current_node is not None:
+        path.append(current_node)
+        current_node = previous_nodes[current_node]
+    path.reverse()
+    return path if path[0] == startNode else []
+
+if __name__ == "__main__":
+    graphInfo = {
+        'adj': {
+            'A': ['B', 'C', 'D'],
+            'B': ['D', 'E'],
+            'C': ['D', 'F'],
+            'D': ['A', 'E', 'F'],
+            'E': ['D', 'I'],
+            'F': ['J', 'K'],
+            'G': ['I'],
+            'H': ['G', 'L'],
+            'I': ['E', 'H', 'J'],
+            'J': ['H', 'I', 'L'],
+            'K': ['L', 'M'],
+            'L': ['M'],
+            'M': []
+        },
+        'position': {
+            'A': (100, 300),
+            'B': (200, 200),
+            'C': (200, 400),
+            'D': (300, 300),
+            'E': (400, 200),
+            'F': (400, 400),
+            'G': (600, 100),
+            'H': (700, 200),
+            'I': (500, 200),
+            'J': (500, 300),
+            'K': (600, 400),
+            'L': (700, 300),
+            'M': (700, 400)
+        },
+        'edges': {
+            'A': [3, 4, 5],
+            'B': [1, 4],
+            'C': [5, 1],
+            'D': [5, 2, 2],
+            'E': [1, 1],
+            'F': [1, 2],
+            'G': [1],
+            'H': [1, 2],
+            'I': [2, 1, 2],
+            'J': [1, 2, 4],
+            'K': [3, 8],
+            'L': [4],
+            'M': []
+        },
+        'goals': ['M']
+    }
+    world = CreateGraphWorld(worldName="Dijkstra's Algorithm", worldInfo=graphInfo, radius=30)
+    world.constructWorld()
+    agent = GraphAgent(world, agentName="TraversalAgent", heatMapView=False)
+    agent.setStartState('A')
+    world.setAgent(agent)
+    def sim():
+        print("Starting the simulation!")
+        distances, previous_nodes = dijkstra('A', world, agent)
+
+        # Create a table to display shortest distances and paths
+        table = PrettyTable(['Node', 'Shortest Distance from A', 'Path'])
+        for node in world.nodeMap.keys():
+            path = get_path(previous_nodes, 'A', node)
+            table.add_row([node, distances[node], " -> ".join(path)])
+        print(table)
+        print("Simulation Completed!")
+    agent.setAlgorithmCallBack(sim)
+    world.showWorld()