05: Doesn’t He Have Intern-Elves For This?

df <- readLines("input.txt")

Warning in readLines("input.txt"): incomplete final line found on 'input.txt'

Part 1

dt <- df
dt <- dt[!grepl("(ab)|(cd)|(pq)|(xy)", dt)]
dt <- dt[grepl("(\\w*[aeuio]\\w*){3,}", dt)]
dt <- dt[grepl("(.)\\1+", dt)]
length(dt)

[1] 255

Part 2

dt <- df
dt <- dt[grepl("(..).*(\\1)", dt, perl = TRUE)]
dt <- dt[grepl("(.)(.)(\\1)", dt, perl = TRUE)]
length(dt)

[1] 55