(defun main []
    // Day 1
    // TODO implement unless
    (let [p (pairWithSum 2020 [1721 979 366 299 675 1456])]
        (when !(and (has p 1721) (has p 299))
            (throw "pairWithSum is broken")))
    (let [[a b] (pairWithSum 2020 (readInts "src/year2020/inputs/day1-1.txt"))]
        (when !(= 545379 (* a b))
            (throw "pairWithSum is broken")))
    (let [t (trioWithSum 2020 [1721 979 366 299 675 1456])]
        (when !(and (has t 675) (has t 366) (has t 979))
            (throw "trioWithSum is broken")))
    (let [[a b c] (trioWithSum 2020 (readInts "src/year2020/inputs/day1-1.txt"))]
        (when !(= 257778836 (* a b c))
            (throw "trioWithSum is broken"))))

(defun readLines [file]
    (.filter
        (.map
            // TODO implement escape sequences in kiss string literals
            (.split (File.getContent file) #|"\n"|#)
            StringTools.trim)
        (lambda [l] (< 0 l.length))))

(defun readInts [file] (let [lines (readLines file)] (lines.map Std.parseInt)))

(defun :kiss.List<Int> pairWithSum [sum :kiss.List<Int> numbers]
    // Put the numbers in a map for random access. This gives an O(n) solution
    (deflocal :Map<Int,Int> numbersMap (new Map))
    (doFor number numbers
        (dict-set numbersMap number (- sum number))
        (let [requiredForPair (dict-get numbersMap number)]
            (when (numbersMap.exists requiredForPair)
                (return [number requiredForPair]))))
    null)

(defun :kiss.List<Int> trioWithSum [sum :kiss.List<Int> numbers]
    (deflocal &mut trio null)
    (doFor number numbers
        (let [requiredForTrio (- sum number)
                pairThatSatisfies (pairWithSum requiredForTrio numbers)]
            (when pairThatSatisfies
                (return [number (nth pairThatSatisfies 0) (nth pairThatSatisfies 1)]))))
    null)