search.py

@@ -4,6 +4,7 @@ Pacman agents (in searchAgents.py).
 
 Please only change the parts of the file you are asked to.  Look for the lines
 that say
+
 "*** YOUR CODE HERE ***"
 
 Follow the project description for details.
@@ -87,7 +88,7 @@ def depthFirstSearch(problem: SearchProblem):
     curr_state = problem.getStartState()
     isGoal = problem.isGoalState(curr_state)
 
-    visited = list([curr_state])
+    visited = set([curr_state])
     stack = util.Stack()
 
     while not isGoal:
@@ -106,7 +107,7 @@ def depthFirstSearch(problem: SearchProblem):
         else:
             obj = stack.pop()
             (curr_state, direction, cost) = obj['state']
-            visited.append(curr_state)
+            visited.add(curr_state)
             actions = obj['actions'] + [ direction ]
             isGoal = problem.isGoalState(curr_state)
 
@@ -122,16 +123,15 @@ def breadthFirstSearch(problem: SearchProblem):
     curr_state = problem.getStartState()
     isGoal = problem.isGoalState(curr_state)
 
-    visited = list([curr_state])
+    visited = set([curr_state])
     queue = util.Queue()
 
     while not isGoal:
-        print(curr_state)
         # push in the Stack
         successors = problem.getSuccessors(curr_state)
         for (state, direction, cost) in successors:
             if state not in visited:
-                visited.append(state)
+                visited.add(state)
                 queue.push({
                     'state': (state, direction, cost),
                     'actions': actions
@@ -158,7 +158,7 @@ def uniformCostSearch(problem: SearchProblem):
     isGoal = problem.isGoalState(curr_state)
     costs = 0
 
-    visited = list([curr_state])
+    visited = set([curr_state])
     queue = util.PriorityQueue()
 
     while not isGoal:
@@ -178,7 +178,7 @@ def uniformCostSearch(problem: SearchProblem):
         else:
             obj = queue.pop()
             (curr_state, direction, cost) = obj['state']
-            visited.append(curr_state)
+            visited.add(curr_state)
             actions = obj['actions'] + [ direction ]
             costs = obj['costs'] + cost
 
@@ -197,41 +197,7 @@ def nullHeuristic(state, problem=None):
 def aStarSearch(problem: SearchProblem, heuristic=nullHeuristic):
     """Search the node that has the lowest combined cost and heuristic first."""
     "*** YOUR CODE HERE ***"
-    actions = []
+    util.raiseNotDefined()
-
-    curr_state = problem.getStartState()
-    isGoal = problem.isGoalState(curr_state)
-    costs = 0
-
-    visited = list([curr_state])
-    queue = util.PriorityQueue()
-
-    while not isGoal:
-        # push in the P Queue
-        successors = problem.getSuccessors(curr_state)
-        for (state, direction, cost) in successors:
-            if state not in visited:
-                queue.push({
-                    'state': (state, direction, cost),
-                    'actions': actions,
-                    'costs': costs
-                }, costs + cost + heuristic(state, problem))                # if visited this successor node, how much cost will the agent need
-
-        # check whether reachable
-        if queue.isEmpty():
-            return []
-        else:
-            obj = queue.pop()
-            (curr_state, direction, cost) = obj['state']
-            visited.append(curr_state)
-            actions = obj['actions'] + [ direction ]
-            costs = obj['costs'] + cost
-
-            isGoal = problem.isGoalState(curr_state)
-
-    return actions
-    
-
 
 
 # Abbreviations

searchAgents.py

@@ -281,17 +281,14 @@ class CornersProblem(search.SearchProblem):
         space)
         """
         "*** YOUR CODE HERE ***"
-        return {
+        util.raiseNotDefined()
-                'position': self.startingPosition,
-                'target_corners': self.corners,
-            }
 
     def isGoalState(self, state: Any):
         """
         Returns whether this search state is a goal state of the problem.
         """
         "*** YOUR CODE HERE ***"
-        return len(state['target_corners']) == 0
+        util.raiseNotDefined()
 
     def getSuccessors(self, state: Any):
         """
@@ -314,24 +311,7 @@ class CornersProblem(search.SearchProblem):
             #   hitsWall = self.walls[nextx][nexty]
 
             "*** YOUR CODE HERE ***"
-            x, y = state['position']
-            dx, dy = Actions.directionToVector(action)
-            nextx, nexty = int(x + dx), int(y + dy)
-            hitsWall = self.walls[nextx][nexty]
 
-            if not hitsWall:
-                # new state (position, corners)
-                if (nextx, nexty) in state['target_corners']:
-                    new_corners = tuple( i for i in state['target_corners'] if i != (nextx, nexty) ) # remove the corner which reached
-                else:
-                    new_corners = state['target_corners']
-
-                new_state = {
-                    'position': (nextx, nexty),
-                    'target_corners': new_corners,
-                }
-
-                successors.append((new_state, action, 1))
 
         self._expanded += 1 # DO NOT CHANGE
         return successors