Lucky and even lucky numbers: Difference between revisions

<small>Note that in the following explanation list indices are assumed to start at ''one''.</small>

 

* Sequence [https://oeis.org/A045954 A045954 even lucky numbers or ELN] on The On-Line Encyclopedia of Integer Sequences.

* Entry [http://mathworld.wolfram.com/LuckyNumber.html lucky numbers] on The Eric Weisstein's World of Mathematics.<br><br>

 

=={{header|Haskell}}==

 

Haskell is a very nice language for this problem because it is a lazy language. Here regular expressions and data types are used.

import System.Environment

import Text.Regex.Posix

 

 

nth :: Int -> Lucky -> Int

 

range :: Int -> Int -> Lucky -> [Int]

_ -> do

putStrLn "Invalid input, wrong number of arguments"

{{out}}

<pre>$ luckyNumbers 1 20

Implementation:

 

1 luckySeq y

:

)

 

 

Task:

 

1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79

program 1 20,evenLucky

6009 6019 6031 6049 6055 6061 6079 6093

program 6000,-6100,evenLucky

 

Note that I've used the J command line rather than a unix or windows command line. This is because J is portable to a wide variety of environments (including phones) and there's no reliably common command line that exists across all these environments. Therefore, J must provide its own, and J's command line requires some slight syntax changes from the suggestions implicit in this task.

 

 

}

}

 

 

 

}

 

}

 

}

 

{{out}}

<pre>$ ./lucky

$ ./lucky 20 , lucky

79

$ ./lucky 10000

115591

111842</pre>

 

=={{header|Python}}==

The generator

 

def lgen(even=False, nmax=1000000):

# drain

for i in lst[n:]:

 

The argument handler

import sys, re

 

 

if __name__ == '__main__':

 

{{out}}

# Output when arguments are: 10000 , evenLucky

Single 10000'th even lucky number: 111842</pre>

 

=={{header|REXX}}==

This REXX version does extra error checking for the arguments.

parse arg bot top func _ . /*obtain required & optional arguments.*/

say func 'number's":" bot top '───►' $lucky(bot, top, func, _)

/*──────────────────────────────────────────────────────────────────────────────────────*/

if f\=='LUCKY' & f\=='EVENLUCKY' then return 'function not valid: ' f

if arg()>3 & ?\='' then return "too many arguments entered: " ?

if \datatype(y,'W') then return "2nd argument isn't an integer: " y

if x>ay then return "2nd argument is less than 1st arg."

/* [↓] build LUCKY | EVENLUCKY*/

do j=1 until j>=yL /*construct list pos. integers.*/

else nop /*balance the IF-THEN logic.*/

else if j //8==0 then iterate /*prune next if mod 8 ≡ zero.*/

end /*j*/

q=0

if q># then leave /*if integer is too large, stop*/

end /*p*/

@.=

@.0=k-1

do m=1 for # /*restrict the found integers. */

end /*m*/ /* [↑] a list of #s or a range*/

_=

<pre>

lucky numbers: 1 20 ───► 1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79

</pre>

<pre>

evenLucky numbers: 1 20 ───► 2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76

</pre>

<pre>

lucky numbers: 6000 -6100 ───► 6009 6019 6031 6049 6055 6061 6079 6093

</pre>

<pre>

evenLucky numbers: 6000 -6100 ───► 6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092

</pre>

<pre>

lucky number: 10000 ───► 115591

</pre>

<pre>

evenLucky number: 10000 ───► 111842

</pre>

 

=={{header|Ruby}}==

{{trans|Python}}

start = even ? 2 : 1

Enumerator.new do |y|

if __FILE__ == $0

lucky(ARGV)

 

{{out}}

10000th even lucky number: 111842

</pre>

 

=={{header|Tcl}}==

{{works with|Tcl|8.6}}

{{trans|Python}}

package require Tcl 8.6

 

} else {

puts "$from'th to $to'th $evenOdd numbers: [join [collectIndices $l [incr from -1] [incr to -1]] ,]"

{{out}}

<pre>

bash$ lucky.tcl 10000 , evenLucky

10000'th even lucky number = 111842

</pre>

 

=={{header|zkl}}==

The lucky number generator works by chaining filters to a even or odd infinite sequence. So it acts like a sieve as each starting number percolates through the filters. It also means there are lots and lots of filters, which doesn't scale well but works for the examples.

ns,idx:=[a..*,2],2;

vm.yield(ns.next());

}

}

The command line is a bit funky (by Unix standards) so we just hard code it and use exceptions (such as trying to convert "foo" to int) to show the options.

try{

j=cmdLineArgs[0].toInt();

}

}

{{out}}

<pre>