GFY: Math Challenge #2

[kevinale]

I'm not gonna make it a night of brain teasers. This is the last one I post.

Ok. Someone wanted another. So here goes. Pick an integer where four times that number is equal to the original integer whose numbers are reversed.

For example:

      WXYZ * 4 = ZYXW

NOTE: I'm not saying that this integer is 4 digits long. It could be any length.

Good luck.

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holy fuck, this could be an all-nighter

[Lane]

"0" is one possible answer

was it supposed to be a non-negative non-zero integer?

[gezzed]

219978 X 4 = 879912

[kevinale]

Originally posted by gezzed
219978 X 4 = 879912

Good one!

There are two other answers too that are smaller integers. Can you get them?

Originally posted by gezzed
219978 X 4 = 879912

whoa!
show me the script?

[Spunky]

none - the hun gets revenue from pre-paid gallery placements on the top 15 spaces and banners. the rest of thegalleries are free placements.

[SetTheWorldonFire]

0 through 9

[gezzed]

Originally posted by SetTheWorldonFire
0 through 9

only 0 works

1 x 4 = 4 which is not 1 reversed
2 x 4 = 8 which is not 2 reversed

etc.

[kevinale]

Originally posted by gezzed


only 0 works

1 x 4 = 4 which is not 1 reversed
2 x 4 = 8 which is not 2 reversed

etc.

Yes.. 0 works too. There are two more (I forgot 0)..

Give up?

for sure I give up,
I just want to know what kind of script would solve that question =)

[gezzed]

I'll post perl source either today or tomorrow. Not that difficult.

[kevinale]

Originally posted by bdjuf
for sure I give up,
I just want to know what kind of script would solve that question =)

I used PERL.. Here is the script I used. It doesn't have the answers.. I'll post them later..

<pre>

for($i=0; $i<999999; ++$i){
if(checkNum($i)){
print "ANSWER IS $i\n";
#exit(1);
}
}

sub checkNum{
$num = shift;
$num2 = "";
for($j=0; $j<=length($num); ++$j){
$num2 .= substr($num, length($num)-$j, 1);
}
if( ($num*4) hahahaha ($num2*1) ){
return 1;
}
return 0;
}
</pre>

This will print the 4 answers

PS: That "hahaha" is the "= =" without the space

[michaelw]

2178
21978
219978

amateurs

[michaelw]

One minute VB code:

Dim zNew As Variant

For x = 1 To 500000
    zNew = x * 4
    If StrReverse(zNew) = x Then
    Debug.Print x
    End If
Next

[kevinale]

Originally posted by michaelw
2178
21978
219978

amateurs

Those be them.. God job.

[Lane]

2178
21978
219978
2199978
21999978
219999978
2199999978
etc..

[Lane]

shit, micheal beat me

[michaelw]

Originally posted by Lane
shit, micheal beat me