Add Somme3ou5 function

[TD_LISP.git] / exercices / arithmetic.lsp

diff --git a/exercices/arithmetic.lsp b/exercices/arithmetic.lsp
index 160645e3840954a726524daacbd51e2339d3c9de..0d55480f69eb758f476ebd94033c8dcf0a8612ad 100755 (executable)
--- a/exercices/arithmetic.lsp
+++ b/exercices/arithmetic.lsp
@@ -60,19 +60,74 @@
 
 (setq L '(3 7 + 4 2 + *))
 (setq M '(4 3 7 + * 2 -))
+(setq N '(10 10 5 / +))
 (define (calculExp P L)
   (cond
-    ((null? L) P)
-    ((= (first L) '+) (calculExp (cons (+ (first P) (P 1)) (rest (rest P))) (rest L))) 
+    ((null? L) (first P))
+    ; all these conditions could probably be simplified
+    ((= (first L) '+) (calculExp (cons (+ (P 1) (first P)) (rest (rest P))) (rest L)))
     ((= (first L) '-) (calculExp (cons (- (P 1) (first P)) (rest (rest P))) (rest L)))
-    ((= (first L) '*) (calculExp (cons (* (first P) (P 1)) (rest (rest P))) (rest L)))
+    ((= (first L) '*) (calculExp (cons (* (P 1) (first P)) (rest (rest P))) (rest L)))
     ;FIXME: test for divide by zero
     ((= (first L) '/) (calculExp (cons (/ (P 1) (first P)) (rest (rest P))) (rest L)))
-    ((calculExp (cons (first L) P) (rest L)))))    
+    ((number? (first L)) (calculExp (cons (first L) P) (rest L)))))
 (println "calculExp")
 (println (calculExp '() L))
 ;(trace true)
 (println (calculExp '() M))
+(println (calculExp '() N))
+
+;(trace nil)
+
+(setq Q '(+ (* x 0) (* 10 (+ y 0))))
+(define (algsimplificator L)
+  (cond
+    ((null? L) '())
+    ; I'm having hard time to find a way of escaping the '(' and ')' characters 
+    ((= (first L) ) (rest L))
+    ;here is the idea: detect the lower well formed expression: begin with (op and finish with ) where op = + - * / and have only two parameters that are atoms.
+    ;then if it match a know pattern, simplify it by following the matching rule.
+    ;do it again on the upper layer recursively until we only have (op A B) that just match no known simplication rules.
+
+    ))
+(println "algsimplificator")
+;(println algsimplificator(Q))
+
+(define (fibonacci N)
+  (cond
+    ((= N 0) 0)
+    ((= N 1) 1)
+    ((> N 1) (+ (fibonacci (- N 1)) (fibonacci (- N 2))))))
+(println "fibonacci")
+;(println (fibonacci 21))
+;(println (fibonacci 14))
+(println (fibonacci 20))
+(println (time (fibonacci 20)))
+
+;(trace true)
+
+(define (fibo:fibo n)
+  (if (not fibo:mem) (set 'fibo:mem '(0 1)))
+  (dotimes (i (- n 1))
+    ;this create a LIFO (or stack) of all previous fibonnaci serie result values
+    (push (+ (fibo:mem -1) (fibo:mem -2)) fibo:mem -1))
+  (last fibo:mem))
+(println "fibo")
+(println (fibo 20))
+(println (time (fibo 20)))
+
+;(trace nil)
+;(trace true)
+
+(setq S '())
+(define (Somme3ou5 N)
+    (dolist (i (sequence 0 N))
+      (cond
+        ((= (mod i 3) 0) (setq S (cons i S)))
+        ((= (mod i 5) 0) (setq S (cons i S)))))
+    (apply + S))
+(println "Somme3ou5")
+(println (Somme3ou5 100))
 
 ;(trace nil)