Part 1

Read in our puzzle input:

day <- 1

input <- here::here(
  "2022", "input",
  paste0("day_", stringr::str_pad(day, 2, "left", "0"))
  ) |>
  readLines()

vec <- as.integer(input)
breaks <- which(is.na(vec))

pull_diff <- function(x) {
  `-`(sum(vec[1:breaks[x]], na.rm = TRUE),
    ifelse(x > 1, sum(vec[1:breaks[x-1]], na.rm = TRUE), 0L)
  )
}

calories_list <- vapply(seq_along(breaks), pull_diff, 1L)
max(calories_list)

Part 2

sum(tail(sort(calories_list), 3))