I am trying to write code for the Tower of Hanoi problem. But I keep getting index out of range error in my slice inside the recursive function call. What am I doing wrong with my code?

Getting Help
1 
package main

import (
	"fmt"
)

func move(n int, source, target, auxiliary []int) {
	if n > 0 {
		move(n-1, source, auxiliary, target)
		curr := source[len(source)-1]
		target = append(target, curr)
		source = source[:len(source)-1]

		fmt.Printf("%v\n%v\n%v\n", source, auxiliary, target)

		move(n-1, auxiliary, target, source)
	}
}

func main() {
	var (
		a = []int{3, 2, 1}
		b = []int{}
		c = []int{}
	)
	move(3, a, c, b)
}
2

Did you try to use a debugger like delve?

3

I have used the debugger that comes with vs code. The problem I am having is that the length of the slice named source becomes less than 0 for some reason amidst the recursion calls.

4

Where you able to find the reason for this when you used the debugger?

If not, maybe try to work through your algorithm on paper: write down the state of every variable after every step and think hard about why a variable is changed the way it is changed.

Remember: the correctness of an algorithm is not related to the programming language used to implement it.

5

No, I could not find the reason.

I have implemented the same algorithm in Python and Kotlin. It works like a charm for those languages.

I am new to Go programming. I surmise that the change in length of the source slice after I remove the last element from it is not being transmitted amidst the recursion calls. Can this problem be due to the fact that slices are reference type?

6

Does this example of using slices help?

https://play.golang.org/p/rbnOVS9W700

EDIT: I think this example is better.

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7

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