String to INT, redux

[aximbigfan]

Ok, so backstory:

 

I had originally posted asking how a function would work, to convert a string into a number, like below:

a = 1

b = 2

z = 26

aa = 27

zz = 702

aaa = 703

etc...

 

The trick, is that I cannot simply keep incrementing the string in a loop, until it gets the input, and returning how many iterations have run. It needs to be in a "single action", liek below:

 

function let2num3($input)
{
$inputarray = str_split($input);
$inputarray = array_reverse($inputarray, false);
$sumT       = 0;
$i          = 1;

$range = array('a' => 1,  'b' => 2,  'c' => 3,
			   'd' => 4,  'e' => 5,  'f' => 6,
			   'g' => 7,  'h' => 8,  'i' => 9,
			   'j' => 10, 'k' => 11, 'l' => 12,
			   'm' => 13, 'n' => 14, 'o' => 15,
			   'p' => 16, 'q' => 17, 'r' => 18,
			   's' => 19, 't' => 20, 'u' => 21,
			   'v' => 22, 'w' => 23, 'x' => 24,
	           'y' => 25, 'z' => 26
			   );

foreach ($inputarray as $key=>$val)
{
	if ($i==1)
		$sumL = $range[$val];
	else
		$sumL = 26  * $range[$val];
	$sumT = $sumT + $sumL;
	$i++;
}

return $sumT;
}

 

This issue is, that it works up to zz perfectly, but past hat it doesn't return the right number.

 

Help?

 

Thanks,

Chris

[DarkWater]

EDIT: Tell me again how you're getting aaa to be 703?

[aximbigfan]

Is it on less, or one more?

 

I am using this function to verify that my "single action" function is correct.

function slow($input)
{
$string = 'a';
$i = 1;
while ($string != $input)
{
	$string++;
	$i++;
}
return $i;
}

 

When aaa is run through it, it outputs 703.

 

Thanks!

Chris

 

[aximbigfan]

NVM, I got it!!!!!!

 

4 days of work... Into this...

 

function let2num3($input)
{
$inputarray = str_split($input);
$inputarray = array_reverse($inputarray, false);
$sumT       = 0;
$i          = 0;

$range = array('a' => 1,  'b' => 2,  'c' => 3,
			   'd' => 4,  'e' => 5,  'f' => 6,
			   'g' => 7,  'h' => 8,  'i' => 9,
			   'j' => 10, 'k' => 11, 'l' => 12,
			   'm' => 13, 'n' => 14, 'o' => 15,
			   'p' => 16, 'q' => 17, 'r' => 18,
			   's' => 19, 't' => 20, 'u' => 21,
			   'v' => 22, 'w' => 23, 'x' => 24,
	           'y' => 25, 'z' => 26
			   );

foreach ($inputarray as $key=>$val)
{
	$sumL = pow(26, $i) * $range[$val];
	$sumT = $sumT + $sumL;
	$i++;
}

return $sumT ;
}

 

Chris

[rhodesa]

this is what i got:

 

<?php
function let2num3($input)
{
  $letters = range('a','z');
  $total = 0;
  foreach(array_reverse(str_split($input)) as $n=>$letter){
    $sum = array_search($letter,$letters) + 1;
    if($n)
      $sum = (pow(26,$n) * $sum);
    $total += $sum;
  }
  return $total;
}
print let2num3('aa');
?>

[rhodesa]

yours + mine got me this simpler version:

function let2num3($input)
{
  $letters = range('a','z');
  $sum = 0;
  foreach(array_reverse(str_split($input)) as $i=>$letter)
    $sum += pow(26, $i) * (array_search($letter,$letters) + 1);
  return $sum;
}
print let2num3('zz');

[sasa]

or

<?php
function str2int($in){
$out = round(pow(26, strlen($in))/25);
$l = range('a', 'z');
$l = array_flip($l);
$tmp = 0;
for ($i = 0; $i<strlen($in); $i++){
	$tmp = $tmp * 26 + $l[$in[$i]];
}
return $out + $tmp;
}

function int2str($in){
$l = range('a', 'z');
$len = 0;
$base = 1;
while ($in >= $base){
	$len++;
	$in -= $base;
	$base *= 26;
}
$out = '';
for ($i = 0; $i < $len; $i++){
	$out = $l[$in % 26]. $out;
	$in = (int) $in / 26;
}
return $out;
}

echo int2str(335115), "\n";
echo str2int('zz') 
?>

[Mark Baker]

Unless I'm missing something, these still all seem long and complex using ranges of A-Z values and powers and reversing the string:

<?php

function columnIDToColumnIndex($columnID) {
$columnIndex = 0;
foreach(str_split(strtoupper($columnID)) as $value) {
	$columnIndex = $columnIndex * 26 + (ord($value) - 64);
}
return $columnIndex;
}

?>

[aximbigfan]

Thanks Sasa, I did need an int to str function!

 

 

Chris