The abs() function in most languages does one thing: give the positive version of the input. Most of the times this is done using something similar to
int
abs (int i)
{
return i < 0 ? -i : i;
}
I was wondering if there is any way to do this with less bytes. Note that this doesn't have to be more efficient, just smaller
Edit: i forgot to add that you can't use the abs() function in your language
√(AnsAns
Square root of input * input. Alternatively, √(Ans² is also 3 bytes.
(x^2)^.5 is 8 bytes. Another 9-byter (if we don't care about vectorization) is max(x,-x) or if we do care about vectorization, pmax(x,-x) for 10 bytes.
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abs in R returns the magnitude of complex inputs, so none of these quite works the same as the R version.
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[N
S S N
_Create_Label_LOOP][S S S N
_Push_0][S N
S _Duplicate][T N
T S _Read_STDIN_as_character][T T T _Retrieve][S N
S _Duplicate][S S S T S T T S T N
_Push_45_-][T S S T _Subtract][N
T S N
_If_0_jump_to_Label_LOOP][T N
S S _Print_as_character][N
S N
N
_Jump_to_Label_LOOP]
Letters S (space), T (tab), and N (new-line) added as highlighting only.
[..._some_action] added as explanation only.
Try it online (with raw spaces, tabs and new-lines only).
Explanation in pseudo-code:
Start LOOP:
Character c = STDIN as character
if(c == '-')
Go to next iteration of LOOP
Print c
Go to next iteration of LOOP
Old 48 bytes answer:
[S S S N
_Push_0][S N
S _Duplicate][T N
T T _Read_STDIN_as_integer][T T T _Retrieve][S N
S _Duplicate][N
T T S N
_If_negative_jump_to_Label_NEG][N
S N
N
_Jump_to_Label_PRINT][N
S S S N
_Create_Label_NEG][S S T T N
_Push_-1][T S S N
_Multiply][N
S S N
_Create_Label_PRINT][T N
S T _Print_as_integer]
Letters S (space), T (tab), and N (new-line) added as highlighting only.
[..._some_action] added as explanation only.
Try it online (with raw spaces, tabs and new-lines only).
Explanation in pseudo-code:
Integer i = STDIN as integer
if(i is negative)
i = i * -1
Jump to function PRINT
else
Jump to function PRINT
function PRINT:
Print i as integer to STDOUT
nt
Explanation:
n # Square
# i.e. 5 → 25
# i.e. -5 → 25
t # Square-root
# 25 → 5
s/-//
Strip the negative sign
n->n<0?n*-1:n
Boring, but can't be done shorter without Math. or using -n directly (a.f.a.i.k.).
-n
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Commented
May 30, 2018 at 9:47
Anonymous tacit prefix function.
%* The argument (implicit) divided by its sign. Try it online! Handles complex numbers as well.
There are a few interesting approaches to this. All are anonymous tacit prefix functions. H.PWiz added two more.
⊢×× The argument multiplied by its sign. Try it online!
⊢⌈- Max of the argument and its negation. Try it online!
⊢∧× The LCM of the argument and its sign. Try it online!
⊢∨- The GCD of the argument and its negation. Try it online!
⊢÷× The argument divided by its sign. Try it online! Handles complex numbers but needs ⎕DIV (Division method) set to 1.
Multiply input by its sign.
*g
Another square/root solution.
²q
Slightly less trivial 4 byte solution: convert to string, remove non-digit characters and convert back to integer. Or, if input can be taken as a string, this one can simply be r-.
sr\D
abs(i)is the shortest, and for those languages that requireMath.abs(i)like Java, .NET, JS, etc.i<0?-i:iis the shortest. \$\endgroup\$abs. Not a tips question to see if there is anything shorter thani<0?-i:ias alternative? \$\endgroup\$abs, without usingabsori<0?-i:i\$\endgroup\$