Building a Japanese Numeral Reading System on PHP - php

Question

I faced an interview question which i felt was very good. Couldn't achieve the complete answer, however, felt sharing and asking the right method to code it in PHP.
The question goes as :
Given the Japanese numeral reading system, write a program that converts an integer into the equivalent Japanese reading.
Basic numeral readings:
1: ichi
2: ni
3: san
4: yon
5: go
6: roku
7: nana
8: hachi
9: kyuu
10: juu
20: ni-juu
30: san-juu
100: hyaku
1000 : sen
10,000: man
100,000,000: oku
1,000,000,000,000: chou
10,000,000,000,000,000: kei
Exceptions due to voice rounding in Japanese reading:
300: sanbyaku
600: roppyaku
800: happyaku
3000: sanzen
8000: hassen
1,000,000,000,000: itchou
8,000,000,000,000: hatchou
10,000,000,000,000: jutchou (also applies to multiplies of 10,000,000,000,000)
10,000,000,000,000,000: ikkei
60,000,000,000,000,000: rokkei
80,000,000,000,000,000: hakkei
100,000,000,000,000,000: jukkei (also applies to multiplies of 10,000,000,000,000,000)
1,000,000,000,000,000,000: hyakkei (also applies to multiplies of 1,000,000,000,000,000,000)
Starting at 10,000, numbers begin with ichi if no digit would otherwise precede, e.g. 1,000 is sen but 10,000 is ichi-man.
Examples:
11: juu ichi
17: juu nana
151: hyaku go-juu ichi
302: san-byaku ni
469: yon-hyaku roku-juu kyuu
2025 : ni-sen ni-juu go
10,403: ichi-man yon-byaku san
41,892: yon-juu ichi-man happyaku kyuu-juu ni
80,000,000,000,000: hachi-jutchou
The code that i have tried is :
$inputNumber = 2025;
$inputString = (String)$inputNumber;
$numeralReadings = array(
1 => 'ichi',
2 => 'ni',
3 => 'san',
4 => 'yon',
5 => 'go',
6 => 'roku',
7 => 'nana',
8 => 'hachi',
9 => 'kyuu',
10 => 'juu',
20 => 'ni-juu',
30 => 'san-juu',
100 => 'hyaku',
1000 => 'sen',
10000 => 'man',
100000000 => 'oku',
1000000000000 => 'chou',
10000000000000000 => 'kei'
);
$numeralExceptions = array(
300 => 'sanbyaku',
600 => 'roppyaku',
800 => 'happyaku',
3000 => 'sanzen',
8000 => 'hassen',
1000000000000 => 'itchou',
8000000000000 => 'hatchou',
10000000000000 => 'jutchou',
10000000000000000 => 'ikkei',
60000000000000000 => 'rokkei',
80000000000000000 => 'hakkei',
100000000000000000 => 'jukkei',
1000000000000000000 => 'hyakkei'
);
if ($inputString > 10000) {
$inp1 = floor($inputString / 1000);
$inp = $inputString - ($inp1 * 1000);
if($inp !== 0) {
read($inp1, $numeralReadings, $numeralExceptions, false);
read($inp, $numeralReadings, $numeralExceptions);
} else {
read($inputString, $numeralReadings, $numeralExceptions);
}
} else {
read($inputString, $numeralReadings, $numeralExceptions);
}
function read($inputStr, $numeralReadings, $numeralExceptions, $parse1 = true)
{
$splitString = str_split($inputStr);
$returnString = '';
$appendIchi = false;
$firstNumber = null;
foreach ($splitString as $key => $number) {
if ($firstNumber == null) {
$firstNumber = $number;
}
if ($number !== 0) {
$int = 1;
$a = count($splitString) - 1 - $key;
for ($i = 0; $i < $a; $i++) {
$int = $int * 10;
}
$tempNumber = (int)$number * $int;
if (isset($numeralExceptions[$tempNumber])) {
$returnString .= $numeralExceptions[$tempNumber] . ' ';
continue;
}
if (isset($numeralReadings[$tempNumber])) {
if ($parse1 == false && $tempNumber == 1) {
continue;
}
$returnString .= $numeralReadings[$tempNumber] . ' ';
continue;
}
if (isset($numeralReadings[(int)$number])) {
if ($parse1 == false && $tempNumber == 1) {
continue;
}
$returnString .= $numeralReadings[(int)$number];
if ($int !== 1) {
$returnString .= '-' . $numeralReadings[$int];
}
$returnString .= ' ';
}
}
}
echo $returnString;
}
here is a fiddle that shows the code in running. You might want to try it online. Link
With the code above, i was able to achieve all the examples stated above other than the last 2.
Anyone who can solve this in a better way?

Answer 1

I guess you can simply use array_key_exists() here
function read($inputStr, $numeralReadings, $numeralExceptions)
{
if(array_key_exists($inputStr, $numeralReadings))
{
return $numeralReadings[$inputStr];
}
else if(array_key_exists($inputStr, $numeralExceptions))
{
return $numeralExceptions[$inputStr];
}
else
{
return "not found";
}
}