unionx

;;;;;; iteration in common lisp


;;;; do
;; `do` is like `if` in c

(do ((x 1 (+ x 1))
     (y 1 (* y 2)))
    ((> x 5) y)  ;; when x is bigger than 5, return y
  (print y)

stribika

#!/usr/bin/python3 -O

from math import floor, log

def montgomery_ladder(x, n, op, select):
    k = floor(log(n, 2)) + 1
    x1 = x
    x2 = op(x, x)
    for i in range(k - 2, -1, -1):
        bit = 1 if n & (1 << i) else 0