Day 1

Data

The list of calories of all items carried by the elves.

data_in_file <- here("DATA", "2022", "input_day_01.txt")

(calories_raw <- read_table(
  data_in_file,
  col_names = FALSE,
  skip_empty_rows = FALSE,
  show_col_types = FALSE
))

# A tibble: 2,240 × 1
      X1
   <dbl>
 1  2991
 2 13880
 3 13279
 4  1514
 5  9507
 6    NA
 7  6544
 8  9672
 9 13044
10  4794
# ℹ 2,230 more rows

Each elf inputs the calories their carrying in column, separating their items from the previous ones by an empty line.

What an idea these elves had! I wonder which programming language they used?!

Separate elves

Each NA means new elf.

calories_new <- calories_raw %>%
  rename(calories = X1) %>%
  mutate(is_na = is.na(calories)) %>%
  mutate(which_elf = cumsum(is_na) + 1)
calories_new

# A tibble: 2,240 × 3
   calories is_na which_elf
      <dbl> <lgl>     <dbl>
 1     2991 FALSE         1
 2    13880 FALSE         1
 3    13279 FALSE         1
 4     1514 FALSE         1
 5     9507 FALSE         1
 6       NA TRUE          2
 7     6544 FALSE         2
 8     9672 FALSE         2
 9    13044 FALSE         2
10     4794 FALSE         2
# ℹ 2,230 more rows

Count calories

calories_new %>%
  group_by(which_elf) %>%
  summarise(sum_cal = sum(calories, na.rm = TRUE)) %>%
  arrange(desc(sum_cal))

# A tibble: 245 × 2
   which_elf sum_cal
       <dbl>   <dbl>
 1       213   68467
 2       234   68143
 3        89   66810
 4        34   66631
 5       209   65461
 6       199   64966
 7       145   64176
 8       140   63815
 9       110   63338
10       150   63104
# ℹ 235 more rows

🥳 TADA!