#!/bin/bash

#-------------------------------------------------------------------------------
# Example 1 for Bash Tips show 17: Negative indices
#-------------------------------------------------------------------------------

#
# Seed the Fibonacci sequence in an indexed array
#
declare -a fib=(0 1 1)

#
# Populate the rest up to (and including) the 20th element
#
for ((i = 3; i <= 20; i++)); do
    fib[$i]=$((fib[i-2]+fib[i-1]))
done

#
# Show the whole array
#
echo "Fibonacci sequence"
echo "${fib[*]}"
echo

#
# Print a few elements working backwards
#
for i in {-1..-4}; do
    echo "fib[$i] = ${fib[$i]}"
done

exit