ujihisa · August 23, 2011 02:25 · Aug 23, 2011
diff --git a/l99 b/l99
@@ -0,0 +1,54 @@
+(defn my-last [xs]
+  (cond
+    (empty? (rest xs)) (first xs)
+    :otherwise (recur (rest xs))))
+(println
+  (my-last '(a b c d)))
+
+(defn my-but-last [xs]
+  (cond
+    (empty? (rest (rest xs))) xs
+    :otherwise (recur (rest xs))))
+(println
+  (my-but-last '(a b c d)))
+
+(defn element-at [xs n]
+  (cond
+    (empty? xs) "failed"
+    (= n 1) (first xs)
+    :otherwise (recur (rest xs) (- n 1))))
+(println
+  (element-at '(a b c d e) 3))
+
+(defn length [xs]
+  (defn length2 [xs n]
+    (cond
+      (empty? xs) n
+      :otherwise (recur (rest xs) (+ n 1))))
+  (length2 xs 0))
+(println
+  (length '(a b c d e)))
+
+(defn my-reverse [xs]
+  (defn reverse2 [xs ys]
+    (cond
+      (empty? xs) ys
+      ;:otherwise (recur (rest xs) (cons (first xs) ys))))
+       :otherwise (recur (rest xs) (conj ys (first xs)))))
+  (reverse2 xs '()))
+(println
+  (my-reverse '(a b c d e)))
+
+(defn palindrome? [xs]
+  (= xs (my-reverse xs)))
+(println
+  (palindrome? '(a b c d e)))
+(println
+  (palindrome? '(a b c b a)))
+
+(defn my-flatten [xs]
+  (cond
+    (list? (first xs)) 
+    :otherwise 2))
+(println
+  (my-flatten '((a b) c (d (e)))))