We are given two 3-digit numbers called S (start) and G (goal), and also a set of 3-digit numbers called

forbidden. To solve the puzzle, we want to get from S to G in the fewest possible moves. A move consists

of transforming a number into another by adding or subtracting 1 to one of its digits. For example, a move

can take you from 123 to 124, or from 953 to 853. Moves are subjects to the following constraints:

• You cannot add to the digit 9 or subtract from the digit 0

• You cannot make a move that transforms the current number into one of the forbidden numbers

• You cannot change the same digit twice in two successive moves.-We are given two 3-digit numbers called S (start) and G (goal), and also a set of 3-digit numbers called

forbidden. To solve the puzzle, we want to get from S to G in the fewest possible moves. A move consists

of transforming a number into another by adding or subtracting 1 to one of its digits. For example, a move

can take you from 123 to 124, or from 953 to 853. Moves are subjects to the following constraints:

•　You cannot add to the digit 9 or subtract from the digit 0

•　You cannot make a move that transforms the current number into one of the forbidden numbers

•　You cannot change the same digit twice in two successive moves.