Data commit

Task/Run-length-encoding/Ol/run-length-encoding-1.ol

@@ -0,0 +1,14 @@
+(define (RLE str)
+   (define iter (string->list str))
+   (let loop ((iter iter) (chr (car iter)) (n 0) (rle '()))
+      (cond
+         ((null? iter)
+            (reverse (cons (cons n chr) rle)))
+         ((char=? chr (car iter))
+            (loop (cdr iter) chr (+ n 1) rle))
+         (else
+            (loop (cdr iter) (car iter) 1 (cons (cons n chr) rle))))))
+
+(define (decode rle)
+   (apply string-append (map (lambda (p)
+      (make-string (car p) (cdr p))) rle)))

Task/Run-length-encoding/Ol/run-length-encoding-2.ol

@@ -0,0 +1,8 @@
+(define str "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW")
+(print str)
+
+(define rle (RLE str))
+(for-each (lambda (pair)
+      (print (car pair) " : " (string (cdr pair))))
+   rle)
+(print (decode rle))