Clojurians Log v2

(defn distance [[x0 y0 z0] [x1 y1 z1]]
  (+ (Math/abs (- x0 x1))
     (Math/abs (- y0 y1))
     (Math/abs (- z0 z1))))

"Elapsed time: 9046.938164 msecs"

(defn distance [[x0 y0 z0] [x1 y1 z1]]
  (+ (Math/abs ^long (- x0 x1))
     (Math/abs ^long (- y0 y1))
     (Math/abs ^long (- z0 z1))))

"Elapsed time: 291.773856 msecs"

Yep, I've learned to turn on reflection warnings so I can fix ones in the critical path. I know CIDER will point them out when it's enabled, other tools might as well

I made the same discovery on the same function…

(defn distance [p1 p2] (reduce + (map #(Math/abs ^int (- %1 %2)) p1 p2)))

This was day25 where there’s a 4th dimensions and the numbers were low. I guess long is probably better in general, and spliting out the operations would also give a speed up

I learned this lesson with ^Character on day 5: https://github.com/thegeez/clj-advent-of-code-2018/blob/master/src/advent2018/core.clj#L389

was optimizing and cleaning up arjuns 23-2 solution here and there: https://github.com/arjun27/advent-of-code-clojure/blob/master/src/advent/2018/day23.clj https://github.com/akovantsev/adventofcode/blob/master/src/adventofcode/2018/day23_2.clj

@norman you can (defn distance [^ints p1 ^ints p2] there

@thegeez woah, you don't mess around with namespaces :kappa:

c++ guys are laughing at us :opieop:

Really?

I didn’t know ^ints was a thing, but it doesn’t help anything here

actually it is way slower, but primitive hint ^ints is for arrays of primitives

actually, ^ints even throws execution a bit off, as it expects it to be arrays, so having ^int and ^ints at the same time ends up being slower than just ^ints

Performance wise? On peak performance on some of the exercises the JVM might be faster.