Day 01

This problem boils down to being able to parse the input and being able to sum the total calories for each elf. For the parsing I used regex to first get all the calories of one elf with regex \n *\n * which maches anything between two newline characters. Then to convert paragraphs to lines I matched a newline character with any number of whitespaces.

1(defn paragraph-lines
2  "Splits s intro paragraphs and paragraphs to lines"
3  [s]
4  (map (#(string/split % #"\n *")) (string/split s #"\n *\n *")))

Next I needed to sum calories of one elf which is just parsing and summing all the values from one row. And to get all the rows I need to just map this function over the whole data structure.

 1(defn sum-row
 2  "Parses and sums a row"
 3  [row]
 4  (->> (map parse-long row)
 5       (apply +)))
 6
 7(defn total-elf
 8  "Gets the total for each elf"
 9  [s]
10  (map sum-row (paragraph-lines s)))

Part 1

For the first part I needed to sort by descending and take the first result.

1(defn part1
2  "Solution for the first part"
3  [s]
4  (->> (total-elf s)
5       (sort-by -)
6       (first)))

Part 2

For the second just take the top three results and sum them up

1(defn part2
2  "Solution for the second part"
3  [s]
4  (->> (total-elf s)
5       (sort-by -)
6       (take 3)
7       (apply +)))