fractal-trees-all.sh

#!/usr/bin/env bash

declare -A a

# credits to https://github.com/MaskRay/HackerRank/blob/master/shell/fractal-trees-all.sh
# d - depth
# l = length
# r = row
# c = column

f() {
    local d=$1 l=$2 r=$3 c=$4
    [[ $d -eq 0 ]] && return
    for ((i=l; i; i--)); do
        a[$((r-i)).$c]=1
    done
    ((r -= l))
    for ((i=l; i; i--)); do
        a[$((r-i)).$((c-i))]=1
        a[$((r-i)).$((c+i))]=1
    done
    f $((d-1)) $((l/2)) $((r-l)) $((c-l))
    f $((d-1)) $((l/2)) $((r-l)) $((c+l))
}
read n
f $n 16 63 49
for ((i=0; i<63; i++)); do
    for ((j=0; j<100; j++)); do
        if [[ ${a[$i.$j]} ]]; then
            printf 1
        else
            printf _
        fi
    done
    echo
done