Scheme solutions for week 137

2 files changed, 68 insertions, 0 deletions

diff --git a/challenge-137/abigail/scheme/ch-1.scm b/challenge-137/abigail/scheme/ch-1.scm
new file mode 100644
index 0000000000..8d37395619
--- /dev/null
+++ b/challenge-137/abigail/scheme/ch-1.scm
@@ -0,0 +1,33 @@
+;;;
+;;; See ../README.md
+;;;
+
+;;;
+;;; Run as: guile --no-auto-compile ch-1.scm
+;;;
+
+(use-modules (ice-9 format))
+
+(define start-years       (list 1600 2000))
+(define long-year-offsets (list
+    004  009  015  020  026 032  037  043  048  054 060  065  071  076  082
+    088  093  099                105  111  116  122 128  133  139  144  150
+    156  161  167  172  178 184  189  195                201  207  212  218
+    224  229  235  240  246 252  257  263  268  274 280  285  291  296  
+              303  308  314 320  325  331  336  342 348  353  359  364  370
+    376  381  387  392  398
+))
+
+(define (check-year start-year offset)
+    (define year (+ start-year offset))
+    (if (and (<= 1900 year) (<= year 2100))
+        (format #t "~d~%" year)))
+
+
+(for-each
+    (lambda (start-year)
+            (for-each
+                (lambda (offset)
+                        (check-year start-year offset))
+                long-year-offsets))
+    start-years)
diff --git a/challenge-137/abigail/scheme/ch-2.scm b/challenge-137/abigail/scheme/ch-2.scm
new file mode 100644
index 0000000000..dc17dee619
--- /dev/null
+++ b/challenge-137/abigail/scheme/ch-2.scm
@@ -0,0 +1,35 @@
+;;;
+;;; See ../README.md
+;;;
+
+;;;
+;;; Run as: guile --no-auto-compile ch-2.scm
+;;;
+
+(use-modules (ice-9 format))
+
+(define (reverse num)
+    (define rev 0)
+    (while (> num 0)
+        (set! rev (* rev 10))
+        (set! rev (+ rev (modulo num 10)))
+        (set! num (truncate (/ num 10)))
+    )
+    rev
+)
+
+(define (ly n)
+    (cond ((>= n 10000000)   1)
+          ((= n (reverse n)) 0)
+          (else (ly (+ n (reverse n))))))
+
+
+(define (main)
+    (define num (read))
+    (if (not (eof-object? num))
+        (begin
+            (format #t "~d~%" (ly num))
+            (main))))
+
+
+(main)