Sum of Squares in Lisp
I need to write a non-recursive version of the开发者_运维百科 function sum-squares and Use a do-loop that is based on the length of the argument list.
Here's how it's done generally:
(defun sum-squares (list) (loop for x in list
for y = (* x x)
summing y into total
finally (return total)))
A do loop solution is even simpler, but not half as elegant:
(defun sum-squares (list)
(let ((sum 0)) (do ((i 0 (1+ i)))
((>= i (length list)))
(setq sum (+ sum (* (nth i list) (nth i list)))))
sum))
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