Add DFS

Author: jackiepiepkorn

2022/FA22/intro-ai-series/workshop-1-ai-search-algorithms/0

@@ -11,13 +11,53 @@ def __init__(self, environment):
     def dfs(self):
         print("Algo: Depth-First Search")
         # TODO: Implement DFS
+        MAPS = {"4x4":["SGFF", "FHFH", "FFFH", "HFFF"],
+        "8x8":["SFFFFFFF", "FFFFFFFF", "FFGHFFFF", "FFFFFHFF",
+               "FFFHFFFF", "FHHFFFHF", "FHFFHFHF", "FFFHFFFF"]}
+        MAP = "8x8" # can be 8x8 or 4x4
+
+        ACTIONS = {0: "LEFT", 1: "DOWN", 2: "RIGHT", 3: "UP"}
+        RENDER_MODE="rgb_array_list"
+        env = gym.make("FrozenLake-v1", desc=MAPS[MAP], render_mode=RENDER_MODE, is_slippery=False)
+        env.action_space.seed(42)
+        observation, info = env.reset(seed=42)
+        stack = [[]]
+        while len(stack) > 0 :
+            acs = stack.pop(0)
+            for i in range(4):
+                rew = -1
+                done = False
+                obs, info = env.reset(seed=42)
+                for a in acs:
+                    obs,rew, terminated, truncated, _ = env.step(a)
+                    if terminated or truncated:
+                        done=True
+                        break
+                if rew > 0.0:
+                    print('Found path by taking following actions: ', acs)
+                    save_video(
+                        env.render(),
+                        "videos/dfs",
+                        fps=env.metadata["render_fps"],
+                        #step_starting_index=step_starting_index,
+                        #episode_index=episode_index,
+                        name_prefix=MAP
+                    )    
+                    env.close()
+                    return acs
+                if done:
+                    break
+                stack.append(acs +[i] )
+        env.close() 
+        print("No sol found")
+        return None
 
 
     def bfs(self):
         print("Algo: Breadth-First Search")
         # TODO: Implement BFS
         MAPS = {"4x4":["SGFF", "FHFH", "FFFH", "HFFF"],
-        "8x8":["SFGFFFFF", "FFFFFFFF", "FFFHFFFF", "FFFFFHFF",
+        "8x8":["SFFFFFFF", "FFFGFFFF", "FFFHFFFF", "FFFFFHFF",
                "FFFHFFFF", "FHHFFFHF", "FHFFHFHF", "FFFHFFFF"]}
         MAP = "8x8" # can be 8x8 or 4x4
 
@@ -42,7 +82,7 @@ def bfs(self):
                     print('Found path by taking following actions: ', acs)
                     save_video(
                         env.render(),
-                        "videos",
+                        "videos/bfs",
                         fps=env.metadata["render_fps"],
                         #step_starting_index=step_starting_index,
                         #episode_index=episode_index,
@@ -65,4 +105,4 @@ def ucs(self):
 
     def a_star(self):
         print("Algo: A* Search")
-        # TODO: Implement A*
+        # TODO: Implement A*