Create state.java

class Point
contains the X and Y co-ordinates of the object
contains an overridden equals class thats checks if the objects X and Y co-ordinates are equal.
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class state
stores the position of object A and B at any given instant of the search.
pathCost stores the cost of objects A movements.
path stores the points(ancestors) A has visited to reach current state.




contains overridden function 'compareTo' for the priority queue to sort itself according to the pathCost.
overidden function 'equals' to check if Point A,B on the board are same.