Recursion· 20 min

Tower of Hanoi

Move n disks in 2ⁿ-1 moves — classic recursion

Setup

Total calls: 1
Step 1 / 189

Current step

1 / 189

hanoi(5, A, C, B) — move 5 disk(s) from A to C using B.

Step log

Peg A
5
4
3
2
1
Peg B
Peg C
hanoi.java
1void hanoi(int n, char from, char to, char via) {
2    if (n == 0) return;
3    hanoi(n-1, from, via, to);
4    System.out.println("Move disk " + n + " from " + from + " to " + to);
5    hanoi(n-1, via, to, from);
6}
● Java

Tower of Hanoi

Move n disks from peg A to peg C using B as auxiliary. Recursive rule: move n-1 disks aside, move the largest, then move n-1 disks on top. Minimum moves: 2ⁿ - 1.

Time
O(2ⁿ)
Space
O(n)
Calls so far
1
Min moves
31
34 / 46