X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=exercices%2Farithmetic.lsp;h=160645e3840954a726524daacbd51e2339d3c9de;hb=5712270167a05905eed75f7cecb0e49af4225537;hp=a3f27ce90d7c99e6e7ca71575b0b7a16d336c6b0;hpb=c4cb602cbbf151134a81d95e6d07a016521cbb48;p=TD_LISP.git

diff --git a/exercices/arithmetic.lsp b/exercices/arithmetic.lsp
index a3f27ce..160645e 100755
--- a/exercices/arithmetic.lsp
+++ b/exercices/arithmetic.lsp
@@ -9,20 +9,22 @@
     ((* P (Puissance1 P (- N 1))))))
 (println "Puissance1")
 (println (Puissance1 5 5))
+(println (Puissance1 2 12))
 
 ;(trace true)
 
 ;O(log N)
 (define (Puissance2 P N)
   (cond
-    ((= N 0) 1)
     ((= N 1) P)
-    ((> N 1)
+    ((= N 2) (* P P))
+    ((> N 2)
      (cond
        ((= (mod N 2) 0) (Puissance2 (Puissance2 P 2) (/ N 2)))
-       ((* P (Puissance2 (Puissance2 P 2) (/ (- 1 N) 2))))))))
+       ((* P (Puissance2 (Puissance2 P 2) (/ (- N 1) 2))))))))
 (println "Puissance2")
-;(println (Puissance2 5 5))
+(println (Puissance2 5 5))
+(println (Puissance2 2 12))
 
 ;(trace nil)
 
@@ -41,29 +43,37 @@
 ;(trace true)
 
 ; https://fr.wikipedia.org/wiki/Coefficient_binomial
-; relation de pascal
+; relation de pascal commenté
 (define (comb N P) 
   (cond
     ((= P 0) 1)
     ((= N P) 1)
-    ((+ (comb (- N 1) P) (comb (- N 1) (- P 1))))))
+    ;((+ (comb (- N 1) P) (comb (- N 1) (- P 1))))))
+    ((/ (* N (comb (- N 1) (- P 1))) P))))
 (println "comb")
 (println (comb 5 4))
 (println (comb 60 4))
+(println "(comb 12 8) = "(comb 12 8))
 
 ;(trace nil)
+;(trace true)
 
 (setq L '(3 7 + 4 2 + *))
-(setq P '())
+(setq M '(4 3 7 + * 2 -))
 (define (calculExp P L)
   (cond
-    ((null? L) 0)
-    ((= (first L) '+) (+ (first P) (calculExp (rest P) (rest L)))) 
-    ((= (first L) '-) (- (first P) (calculExp (rest P) (rest L))))
-    ((= (first L) '*) (* (first P) (calculExp (rest P) (rest L))))
+    ((null? L) P)
+    ((= (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)))
+    ((= (first L) '*) (calculExp (cons (* (first P) (P 1)) (rest (rest P))) (rest L)))
     ;FIXME: test for divide by zero
-    ((= (first L) '/) (/ (first P) (calculExp (rest P) (rest L))))
-    ((cons (first L) (calculExp P (rest L))))))    
-;(println (calculExp P L))
+    ((= (first L) '/) (calculExp (cons (/ (P 1) (first P)) (rest (rest P))) (rest L)))
+    ((calculExp (cons (first L) P) (rest L)))))    
+(println "calculExp")
+(println (calculExp '() L))
+;(trace true)
+(println (calculExp '() M))
+
+;(trace nil)
 
 (exit)