depth first search in Bash script using simple data structures - bash

Question

I'm trying to do as stated above. I have designed a breadth first search with relative ease.
The goal of the script is to create a directory structure of a certain depth and breadth input by the user. I'm trying to alter my breadth first implementation to support depth first search. This is where I got:
depthsearch(){
local open=("seed")
local tmpopen=()
local closed=()
local x="seed"
for((j=0;j<$depth;j++)); do
for x in "${open[#]}" ; do
for ((i=0;i<$breadth;i++)); do
tmpopen=("${tmpopen[#]}" "$x/$i")
mkdir echo "$x/$i"
done
open=("${tmpopen[#]}" "${open[#]:1}")
tmpopen=()
closed=("${closed[#]}" "$x")
done
tmpopen=()
done
}
Okay, so I trimmed down my question a bit. Apparently the problem was that I wasn't iterating by index, so I couldn't update my loop while it was iterating. However, I can't figure out how to iterate by index and update my array so I can construct my directories depth first. Any example would be appreciated.

Answer 1

If it is not strictly necessary to use data structures, you can do it with a simple recusion:
#!/bin/bash
depth=4
breadth=3
node_id=0 #for testing, increments +1 each time a folder is created.
# args: level( [0,depth) ), childNo ( [0,breadth) )
generateTreeDFS(){
declare -i level=$1
declare -i childNo=$2
declare -i i=0
if (( $level < $depth ));then
mkdir "n_$childNo-$node_id"
cd "n_$childNo-$node_id"
let node_id++
let level++
while [ $i -lt $breadth ]
do
generateTreeDFS $level $i
let i++
done
cd ..
fi
}
If we call
generateTreeDFS 0 0
The directory structure will be like this:
$ tree .
.
├── depthsearch.sh
└── n_0-0
├── n_0-1
│   ├── n_0-2
│   │   ├── n_0-3
│   │   ├── n_1-4
│   │   └── n_2-5
│   ├── n_1-6
│   │   ├── n_0-7
│   │   ├── n_1-8
│   │   └── n_2-9
│   └── n_2-10
│   ├── n_0-11
│   ├── n_1-12
│   └── n_2-13
├── n_1-14
│   ├── n_0-15
│   │   ├── n_0-16
│   │   ├── n_1-17
│   │   └── n_2-18
│   ├── n_1-19
│   │   ├── n_0-20
│   │   ├── n_1-21
│   │   └── n_2-22
│   └── n_2-23
│   ├── n_0-24
│   ├── n_1-25
│   └── n_2-26
└── n_2-27
├── n_0-28
│   ├── n_0-29
│   ├── n_1-30
│   └── n_2-31
├── n_1-32
│   ├── n_0-33
│   ├── n_1-34
│   └── n_2-35
└── n_2-36
├── n_0-37
├── n_1-38
└── n_2-39