Implementation of http://programmingpraxis.com/2012/11/27/amazon-interview-question/2/ using a Leftist Priority Queue from here: https://gist.github.com/4299232.js

gistfile1.clj

(ns thornydev.top100.heap
  (:require [thornydev.lib.leftist-heap
             :refer [pq-first pq-rest pq-insert pq-empty]]))

(defn distance [[x y]]
  (+ (java.lang.Math/abs x) (java.lang.Math/abs y)))

(defn dist-lt? [pt1 pt2]
  (< (distance pt2) (distance pt1)))

(defn heap-sift [pq pt]
  (if (dist-lt? pt (pq-first pq))
    pq
    (pq-insert dist-lt? (pq-rest dist-lt? pq) pt)))

(defn top-heap [points max-size]
  (let [[add-all xs] (split-at max-size points)
        init-q (reduce #(pq-insert dist-lt? % %2) pq-empty add-all)]
    (reduce heap-sift init-q xs)))