gistfile1.txt

(defn diag-diff
  [data]
  (let [width (Math/sqrt (count data))
        
        right-seq (take-nth (+ 1 width) data)
        right-diag (take width right-seq)
        
        left-data (drop (- width 1) data)
        left-seq (take-nth (- width 1) left-data)
        left-diag (take width left-seq)
        
        right-sum (reduce + 0 right-diag)
        left-sum (reduce + 0 left-diag)
        ]
    (- left-sum right-sum)
  ))