#!/bin/bash
base_str="____________________________________________________________________________________________________"
str_arr=()
read level
draw_fractal() {
    local current_level=$1
    local row_no=$2
    local pos=$3
    local row_current=$4
    if [ $current_level -eq $level ]; then
        return
    fi
    for ((i = 1; i <= $row_no; i++)); do
       str_arr[$row_current]="${str_arr[$row_current]:0:$pos}1${str_arr[$row_current]:$(($pos + 1))}"
       row_current=$(($row_current + 1))
    done
    for ((i = 1; i <= $row_no; i++)); do
       str_arr[$row_current]="${str_arr[$row_current]:0:$(($pos + $i))}1${str_arr[$row_current]:$(($pos + $i + 1))}"
       str_arr[$row_current]="${str_arr[$row_current]:0:$(($pos - $i))}1${str_arr[$row_current]:$(($pos - $i + 1))}"
       row_current=$(($row_current + 1))
    done
    draw_fractal $(($current_level + 1)) $(($row_no / 2)) $(($pos - $row_no )) $row_current
    draw_fractal $(($current_level + 1)) $(($row_no / 2)) $(($pos + $row_no )) $row_current
}
for (( i=1; i<=64; i++ )); do
    str_arr[i]=$base_str
done

draw_fractal 0 16 49 1

length=${#str_arr[@]}
for (( i=length-1; i>=0; i-- )); do
    echo "${str_arr[i]}"
doner_arr[i]}"
done