Topic: how to insert new value into list

[Stefan]

Code - Auto/Visual Lisp: [Select]

1. (defun f (l n)
2.   (if l
3.     (cons (max n (car l)) (f (cdr l) (min n (car l))))
4.   )
5. )

Wow.. Evgeniy, that is a really beauty piece of code...
I think this thread deserve a "challenge" in front of it..
If some of you will 'benchmark' this, I want to refine my variants:

Code - Auto/Visual Lisp: [Select]

1. (defun ph:f1 (l n)
2.      (if l
3.         (if
4.          (> n (car l))
5.           (cons n (reverse (cdr (reverse l))))
6.           (cons (car l) (ph:f1 (cdr l) n))
7.        )
8.      )
9.     )

Code - Auto/Visual Lisp: [Select]

1. (defun ph:f2 (l n)
2.      (mapcar
3.        (function
4.           (lambda (x / m)
5.             (if (> n x) (setq m n n x x m) x)
6.           )
7.         )
8.       l
9.     )
10.   )

[Lee Mac]

Not for duplicates...

Code - Auto/Visual Lisp: [Select]

1. (defun LM:f1 ( l n ) (reverse (cdr (vl-sort (cons n l) '<))))

[irneb]

Consolidated those which do what the OP asked for. Attached.

Tested each using the TestFunc in attached. Didn't consider duplicates though.

Here's the benchmark tests on the OP's original list:

Code: [Select]

Benchmarking ............... done for 32768 iterations. Sorted from fastest.
Statement                                Increment  Time(ms) Normalize  Relative
--------------------------------------------------------------------------------
(FASTER:INSERTN (QUOTE (10000 9000 8...)     32768      1419      1419      4.93
(PBE:TOPFIVE (QUOTE (10000 9000 8000...)     32768      1481      1481      4.72
(IB:INS-KEEP-LENGTH (QUOTE (10000 90...)     32768      1483      1483      4.71
(LM:F (QUOTE (10000 9000 8000 7000 6...)     32768      1497      1497      4.67
(HB:F (QUOTE (10000 9000 8000 7000 6...)     32768      1513      1513      4.62
(LM:F2 (QUOTE (10000 9000 8000 7000 ...)     32768      1607      1607      4.35
(STEFAN:INS_ITEM_1 (QUOTE (10000 900...)     32768      1621      1621      4.31
(EE:F1 (QUOTE (10000 9000 8000 7000 ...)     32768      1670      1670      4.19
(STEFAN:INS_ITEM (QUOTE (10000 9000 ...)     32768      1701      1701      4.11
(EE:F2 (QUOTE (10000 9000 8000 7000 ...)     32768      1701      1701      4.11
(PBE:TOPFIVE1 (QUOTE (10000 9000 800...)     32768      1824      1824      3.83
(LM:F1 (QUOTE (10000 9000 8000 7000 ...)     32768      1841      1841      3.80
(EE:F (QUOTE (10000 9000 8000 7000 6...)     32768      2012      2012      3.48
(HB:F1 (QUOTE (10000 9000 8000 7000 ...)     16384      1060      2120      3.30
(IB:INSVAL (QUOTE (10000 9000 8000 7...)      8192      1748      6992      1.00
--------------------------------------------------------------------------------

[Lee Mac]

Not for duplicates...

Code - Auto/Visual Lisp: [Select]

1. (defun LM:f1 ( l n ) (reverse (cdr (vl-sort (cons n l) '<))))

Oops! I see that my LM:F1 function above is pretty much the same as pBe's TOPFIVE code...

Code - Auto/Visual Lisp: [Select]

1. (defun TopFive  (lst n)
2.       (if (>  n (last lst))
3.             (reverse
4.                   (cdr (vl-sort
5.                              (cons n lst)
6.                              '<)))
7.             lst)
8.       )

[chlh_jd]

ALL NICE !

Code: [Select]

(defun f (L n)
  (if (> n (car l)) (cons n l)
     (cons (car l) (f (cdr l) n))))
Test

Code: [Select]

(f '(6 5 4 3 2) 1)    ; (6 5 4 3 2 1)
(f '(9 8 7 6 5 3) 1)  ; (9 8 7 6 5 3 1)
(f '(9 8 7 6 5 3) 10) ; (10 9 8 7 6 5 3)
(f '(9 8 7 6 5 3) 3)  ; (9 8 7 6 5 3 3)
(f '(9 8 7 6 5 3) 5)  ; (9 8 7 6 5 5 3)
(f '(9 8 7 6 5 3) 4)  ; (9 8 7 6 5 4 3)
(f '(9 8 7 6 5 3) 9)  ; (9 9 8 7 6 5 3)


Not exactly what the OP asked for. He wanted the list to stay the same length by dropping the smallest value after inserting the new value.

I'm sorry to do wrong the mean .

Code: [Select]

(defun f (l n / f1)
  (defun f1 (L n)
    (if (< n (car l))
      (cons n l)
      (cons (car l) (f1 (cdr l) n))
    )
  )
  (reverse (cdr (f1 (reverse l) n)))
)
My Test result
测试耗时......毫秒 / 相对速度 ...... 迭代次数32768...:
 PH:F1......60 / 15.34......<Fastest>
 LM:F1......160 / 5.75......
 PH:F2......220 / 4.18......
 F......230 / 4.00......
 HB:F......260 / 3.54......
 EA:F......260 / 3.54......
 INSVAL......920 / 1.00......<Slowest>

[chlh_jd]

Code - Auto/Visual Lisp: [Select]

1. (defun ph:f1 (l n)
2.      (if lst
3.        (if
4.          (> n (car l))
5.           (cons n (reverse (cdr (reverse l))))
6.           (cons (car l) (ph:f1 (cdr l) n))
7.        )
8.      )
9.     )

Here's

Code: [Select]

(if lst must be  '(if L'?
New Test result
测试耗时......毫秒 / 相对速度 ...... 迭代次数32768...:
 LM:F1......160 / 5.81......<Fastest>
 PH:F1......160 / 5.81......
 PH:F2......210 / 4.43......
 F......220 / 4.23......
 EA:F......260 / 3.58......
 HB:F......260 / 3.58......
 INSVAL......930 / 1.00......<Slowest>

[Stefan]

Here's

Code: [Select]

(if lst must be  '(if L'?

Edited "in place" and missed that one... sorry.

[pBe]

I prefer:

Code - Auto/Visual Lisp: [Select]

1. (defun f (l n)
2.   (if l
3.     (cons (max n (car l)) (f (cdr l) (min n (car l))))
4.   )
5. )

Incredible. What are they feeding you...  Guess i need to change my diet 

[pBe]

(IB:INSVAL (QUOTE (10000 9000 8000 7...)     

Which  one is this Irné ?

[irneb]

Which  one is this Irné ?

That's the one from my post #27. The IB is my initials  .

BTW: The IB:INS-KEEP-LENGTH is actually not mine but yours (post #5) - just without the if statement as I've noted in post #9. Though I think I got a bit confused by your 2 versions  :ugly: . It should've read: "Basically what pBe did, just ignoring the check for new value smaller than last". Which is why it's so close to yours in the test, yours would be faster if the benchmark considered adding a value smaller than all the rest.

Edit: I'm guessing the timings would start changing drastically as the list sent is larger. But since the list is only 5 items, the usual suspects don't really apply. I'm actually surprised that Elpanov's don't surpass the rest - but that's probably due to the list-length.

[ElpanovEvgeniy]

Only the love of arts... 

Code - Auto/Visual Lisp: [Select]

1. (defun f (l n) (mapcar 'max (mapcar '(lambda (a) (min a n)) (cons n l)) l))

[Lee Mac]

Very original Evgeniy 

A shortened version of my earlier iterative code:

Code - Auto/Visual Lisp: [Select]

1. (defun LM:f2 ( l n / a o )
2.     (while (< n (setq a (car l)))
3.         (setq o (cons a o)
4.               l (cdr l)
5.         )
6.     )
7.     (reverse (append (cdr (reverse (cons n l))) o))
8. )

[bruno_vdh]

Hello,

My variant with mapcar + lambda 

Code: [Select]

(defun bv:f1 (l n / flag)
  (mapcar '(lambda (a b) (if flag b (if (> n a) (setq flag n) a))) l (cons (car l) l))
)
The same for those who prefer cond to if

Code: [Select]

(defun bv:f2 (l n / flag)
  (mapcar '(lambda (a b) (cond (flag b) ((> n a) (setq flag n)) (a))) l (cons (car l) l))
)
Excuse my English, I speak with Google Translation
A+

[RAIN CODE]

another 2

Code - Auto/Visual Lisp: [Select]

1. (defun f (l n) (mapcar '(lambda (a b) (nth a (cons n l))) (vl-sort-i (cons n l) '>) l))

You write very good program. I wish I could write like you do.

Thanks for your help. 

You are one of the best in this swamp forum - no doubt about it.