Merge pull request #68 from Laikokwui/main

solving bottle puzzle using breadth first search

Author: DeadButCoding

algos in python/Informed Search/breadthFirstSearch.py

@@ -0,0 +1,85 @@
+from collections import deque
+ 
+def BFS(b1, b2, initial_state, goal_state):
+    # Map is used to store the states
+    map = {}
+    isSolvable = False
+    path = []
+    
+    queue = deque() # Queue to maintain states
+ 
+    queue.append(initial_state) # Initialing with initial state
+ 
+    while (len(queue) > 0):
+        # Current state
+        current_state = queue.popleft()
+ 
+        # If this state is already visited
+        if ((current_state[0], current_state[1]) in map):
+            continue
+ 
+        # Doesn't met bottle constraints
+        if ((current_state[0] > b1 or current_state[1] > b2 or current_state[0] < 0 or current_state[1] < 0)):
+            continue
+ 
+        # Filling the vector for constructing the solution path
+        path.append([current_state[0], current_state[1]])
+ 
+        # Marking current state as visited
+        map[(current_state[0], current_state[1])] = 1
+ 
+        # Check Goal State
+        if (current_state[0] == goal_state[0] and current_state[1] == goal_state[1]):
+            isSolvable = True
+ 
+            # Print the solution path
+            solution_path = len(path)
+            for i in range(solution_path):
+                print("(", path[i][0], ",", path[i][1], ")")
+            break
+ 
+        # If we have not reached final state start developing intermediate states to reach solution state
+        queue.append([current_state[0], b2])  # Fill Bottle 2
+        queue.append([b1, current_state[1]])  # Fill Bottle 1
+ 
+        for ap in range(max(b1, b2) + 1):
+ 
+            # Pour amount ap from Bottle 2 to Bottle 1
+            c = current_state[0] + ap
+            d = current_state[1] - ap
+ 
+            # Check if this state is possible or not
+            if (c == b1 or (d == 0 and d >= 0)):
+                queue.append([c, d])
+ 
+            # Pour amount ap from Bottle 1 to Bottle 2
+            c = current_state[0] - ap
+            d = current_state[1] + ap
+ 
+            # Check if this state is possible or not
+            if ((c == 0 and c >= 0) or d == b2):
+                queue.append([c, d])
+ 
+        # Empty Bottle 2
+        queue.append([b1, 0])
+ 
+        # Empty Bottle 1
+        queue.append([0, b2])
+ 
+    # No, solution exists if ans=0
+    if (not isSolvable):
+        print(map)
+        print("No solution")
+ 
+
+# Bottle Puzzle solve using BFS
+if __name__ == '__main__':
+ 
+    Bottle1, Bottle2 = 10, 8
+    initial_state = (0,0)
+    goal_state = (2,8)
+    
+    print("Path from initial state " "to solution state ::")
+ 
+    BFS(Bottle1, Bottle2, initial_state, goal_state)
+