C Program for Tower of Hanoi Problem Using Recursion

The Tower of Hanoi (also called the Tower of Brahma or Lucas’ Tower and sometimes pluralized) is a mathematical game or puzzle. It consists of three rods, and a number of disks of different sizes which can slide onto any rod. The puzzle starts with the disks in a neat stack in ascending order of size on one rod, the smallest at the top, thus making a conical shape as shown in below image.

The objective of the puzzle is to move the entire stack to another rod, obeying the following simple rules:

1. Only one disk can be moved at a time.
2. Each move consists of taking the upper disk from one of the stacks and placing it on top of another stack i.e. a disk can only be moved if it is the uppermost disk on a stack.
3. No disk may be placed on top of a smaller disk.

With three disks, the puzzle can be solved in seven moves. The minimum number of moves required to solve a Tower of Hanoi puzzle is 2ⁿ-1, where n is the number of disks.

Animated solution of the Tower of Hanoi Puzzle for T(4,3)

C Program using recursion is given below which finds solution for Tower of Hanoi Problem.

C Program for Tower of Hanoi Problem Using Recursion

#include<stdio.h>

void TOH(int,char,char,char);

void main()
{
	int n;
	printf("How many plates?");
	scanf("%d",&n);
	TOH(n,'A','B','C');
}

void TOH(int n,char x,char y,char z)
{
	if(n>0)
	{
		TOH(n-1,x,z,y);
		printf("\n%c -> %c",x,y);
		TOH(n-1,z,y,x);
	}
}

Output

How many plates?3

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

Source: https://en.wikipedia.org/wiki/Tower_of_Hanoi

Comment below if you have doubts or found anything incorrect related to above program for tower of hanoi in C.