HaskellProjects

tower_of_hanoi

A recursive Tower of Hanoi solver implemented in Haskell. This program demonstrates the classic recursive algorithm to move disks between three pegs following the rules of the puzzle.

⚙️ Build & Run

Make sure GHC is installed. To build and execute:

cd tower_of_hanoi
ghc -O2 tower_of_hanoi.hs -o tower_of_hanoi
./tower_of_hanoi <n>

Example:

cd tower_of_hanoi
ghc -O2 tower_of_hanoi.hs -o tower_of_hanoi
./tower_of_hanoi 3

Output:

'A' --> 'C'
'A' --> 'B'
'C' --> 'B'
'A' --> 'C'
'B' --> 'A'
'B' --> 'C'
'A' --> 'C'

Each line represents a single move from one peg to another.

🧩 How It Works

• Uses recursion to solve the Tower of Hanoi problem for n disks.
• move n s d t recursively transfers disks from source peg s to destination peg d using temporary peg t.
• The base case (move 1 s d t) performs a single move.
• The function call pattern follows the recurrence relation: [ T(n) = 2T(n-1) + 1 ]

🧠 Notes

• The total number of moves required is (2^n - 1).
• Works well for small to medium n; output grows exponentially with larger values.
• Pegs are labeled 'A', 'B', and 'C'.

🪪 Author

Abhrankan Chakrabarti

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