Node.js — File System

1 Read environment variable with default Easy 2 Sum 1..5 #1 Hard 3 Filter evens #2 Medium 4 Map squares #3 Easy 5 Max in set #4 Medium 6 Reduce product #5 Hard 7 Sum 1..10 #6 Medium 8 Filter evens #7 Easy 9 Map squares #8 Medium 10 Max in set #9 Hard 11 Reduce product #10 Medium 12 Sum 1..15 #11 Easy 13 Filter evens #12 Medium 14 Map squares #13 Hard 15 Max in set #14 Medium 16 Reduce product #15 Easy 17 Sum 1..5 #16 Medium 18 Filter evens #17 Hard 19 Map squares #18 Medium 20 Max in set #19 Easy 21 Reduce product #20 Medium 22 Sum 1..10 #21 Hard 23 Filter evens #22 Medium 24 Map squares #23 Easy 25 Max in set #24 Medium 26 Reduce product #25 Hard 27 Sum 1..15 #26 Medium 28 Filter evens #27 Easy 29 Map squares #28 Medium 30 Max in set #29 Hard 31 Reduce product #30 Medium