Data commit

Task/Babbage-problem/Common-Lisp/babbage-problem-1.lisp

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+(defun babbage-test (n)
+ "A generic function for any ending of a number"
+  (when (> n 0)
+    (do* ((i 0 (1+ i))
+          (d (expt 10 (1+ (truncate (log n) (log 10))))) )
+      ((= (mod (* i i) d) n) i) )))

Task/Babbage-problem/Common-Lisp/babbage-problem-2.lisp

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+; Project : Babbage problem
+
+(setq n 1)
+(setq bab2 1)
+(loop while (/= bab2 269696)
+    do (setq n (+ n 1))
+         (setf bab1 (expt n 2))
+         (setf bab2 (mod bab1 1000000)))
+(format t "~a" "The smallest number whose square ends in 269696 is: ")
+(write n)
+(terpri)
+(format t "~a" "Its square is: ")
+(write (* n n))

Task/Babbage-problem/Common-Lisp/babbage-problem-3.lisp

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+;; * The package definition
+(defpackage :babbage
+  (:use :common-lisp))
+(in-package :babbage)
+
+;; * The function
+(defun babbage (end)
+  "Returns the smallest number whose square ends in END."
+  (loop
+     :with digits = (ceiling (log end 10))     ; How many digits has end?
+     :for num :from (isqrt end)                ; The start number
+     :for square = (expt num 2)                ; The square of num
+     :for ends = (mod square (expt 10 digits)) ; The last digits
+     :until (= ends end)
+     :finally
+       (format t "The smallest number whose square ends in ~D is: ~D~%" end num)
+       (format t "Its square is: ~D~%" square)
+       (return num)))