Towers of Hanoi

Objective

Move the whole stack onto peg C (the right-hand peg). Only one disc may move at a time, and a larger disc must never sit on a smaller one.

Rules

• You may only move the top disc of a peg.
• You may place a disc on an empty peg, or onto a larger disc.
• The fewest moves for a full stack of n discs is 2ⁿ − 1 (7 for three discs, 15 for four, 31 for five).

Controls

• Tap a peg to pick up its top disc, then tap the destination peg.
• Keys 1, 2 and 3 do the same for pegs A, B and C.
• Hint makes one move from a shortest solution. Undo takes the last move back.

Difficulty

• Easy: 3 discs — 7 moves if you play perfectly.
• Classic: 4 discs — 15 perfect moves.
• Hard: 5 discs — 31 perfect moves.

Daily challenge

Everyone receives the same seeded scramble of 4, 5 or 6 discs. It resets at midnight UK. The first solve of the day counts for the league and your streak.