Replacing Letters with Hashes

Write a function that replaces all letters within a specified range with the hash symbol #.

Examples

replace("abcdef", "c-e") ➞ "ab###f"

replace("rattle", "r-z") ➞ "#a##le"

replace("microscopic", "i-i") ➞ "m#croscop#c"

replace("", "a-z") ➞ ""

Notes

• The range will always be in order, a.k.a. for m-n, character m will always come before or equal n.
• Strings will be in lower case letters only.
• Return an empty string if the input is an empty string.