Fix the recursive optimized power calculation

[TD_LISP.git] / exercices / lists.lsp

diff --git a/exercices/lists.lsp b/exercices/lists.lsp
index 25360bcf166d051570501485b0e2ed6ddb61c5ca..35590dada335ff070e4a9546859cdafbe8777b1c 100755 (executable)
--- a/exercices/lists.lsp
+++ b/exercices/lists.lsp
@@ -46,11 +46,11 @@
 
 ;(trace true)
 
-(define (rang x L)
-  (if (boolmemrec x L)
+(define (rang E L)
+  (if (boolmemrec E L)
     (cond 
-      ((= x (first L)) 0)
-      ((+ 1 (rang x (rest L)))))
+      ((= E (first L)) 0)
+      ((+ 1 (rang E (rest L)))))
     nil))
 (println "rang/find")
 (println (rang 4 L))
@@ -60,11 +60,11 @@
 
 ;(trace nil)
 
-(define (tete n L) 
+(define (tete N L)
   (cond 
     ((null? L) '())
-    ((= n 0) '())
-    ((cons (first L) (tete (- n 1) (rest L))))))
+    ((= N 0) '())
+    ((cons (first L) (tete (- N 1) (rest L))))))
 (println "tete/slice")
 (println (tete 3 L))
 (println (slice L 0 3))
@@ -118,11 +118,11 @@
 
 (define (aplatir L) 
   (cond
-    ((null? L) nil)
-    ((atom? L) (list L)) ;FIXME: the "casting" is not working properly
+    ((null? L) '())
+    ((atom? L) (list L))
     ((append (aplatir (first L)) (aplatir (rest L))))))
 (println "aplatir/flat")
-;(println (aplatir T))
+(println (aplatir T))
 (println (flat T))
 
 ;(trace nil)
@@ -144,20 +144,20 @@
 (println (reverseL L))
 (println (reverse L))
 
-(define (list< n L)
+(define (list< N L)
   (cond
     ((null? L) '())
-    ((>= (first L) n) (list< n (rest L)))
-    ((cons (first L) (list< n (rest L))))))
+    ((>= (first L) N) (list< N (rest L)))
+    ((cons (first L) (list< N (rest L))))))
 (println "list<")
 (println (list< 5 L))
 (println (list< 5 C))
 
-(define (list>= n L)
+(define (list>= N L)
   (cond
     ((null? L) '())
-    ((< (first L) n) (list>= n (rest L)))
-    ((cons (first L) (list>= n (rest L))))))
+    ((< (first L) N) (list>= N (rest L)))
+    ((cons (first L) (list>= N (rest L))))))
 (println "list>=")
 (println (list>= 5 C))
 
@@ -169,7 +169,7 @@
     ((append 
        ;the pivot is the first element of the list
        (qsort (list< (first L) (rest L))) 
-       (cons (first L) '()) 
+       (list (first L))
        (qsort (list>= (first L) (rest L)))))))
 (println "qsort")
 (println (qsort C))
@@ -180,20 +180,46 @@
 (setq L1 '(A ? ? B C D ?))
 (setq L2 '(? A B ? C ? ? D))
 
-(define (removeC c L)
-  (cond
-    ((null? L) '())
-    ((= c (first L))) (removeC c (rest L))
-    (((cons (first L) (removeC c (rest L)))))))
-(println (removeC A L1))
+;(println "replace")
+;(println L1)
+;(println L2)
+;the replace function modify the passed argument
+;(println (replace 'B L1))
+;(println (replace '? L1))
+;(println (replace '? L2))
+;(println L1)
+;(println L2)
 
 (define (filtre L1 L2 C)
+  ;the replace function modify the passed argument
+  ;FIXME: use the function argument C
+  (replace '? L1)
+  (replace '? L2)
   (cond 
     ((and (null? L1) (null? L2)) true)
     ((and (not (null? L1)) (null? L2)) nil)
     ((and (null? L1) (not (null? L2))) nil)
     ((and (inclu L1 L2) (inclu L2 L1) true))))
-;(println "filtre")
-;(println (filtre L1 L2 ?))
+(println "filtre")
+(println (filtre L1 L2 ?))
+(println (filtre L M ?))
+
+;algorithm written on the board
+(define (filtrerec L1 L2 C)
+  ;FIXME: use the function argument C
+  (cond
+    ((null? L1)
+      (cond
+        ((null? L2) true)
+        ((= '? (first L2)) (filtrerec L1 (rest L2)))
+        (nil)))
+    ((null? L2) (filtrerec L2 L1))
+    ((= '? (first L1)) (filtrerec (rest L1) L2))
+    ((= '? (first L2)) (filtrerec L1 (rest L2)))
+    ((= (first L1) (first L2)) (filtrerec (rest L1) (rest L2)) )
+    (nil)))
+(println "filtrerec")
+(println (filtrerec L1 L2 ?))
+(println (filtrerec L M ?))
 
 (exit)