Sasha Pachev wrote:
> Given a string that could contain arithmetic expressions, with the
> addition that numeric constants could be potentially expressed as
> times, e.g 1:36 for 96 seconds, or 2:10:08 for 2 hours 10 minutes and
> 8 seconds, also decimal fractions after seconds are allowed, e.g
> 3:45.6 or 3:40:50.67, replace all the time values with their
> equivalent number of seconds.
>
> Solution language: Anything you want.
Just for kicks and giggles here is my attempt. Not quite as elegant as
the others, but does the job. I included the one liner version below
just for fun.
===READABLE VERSION===
<?php
//Tests
echo time2sec("1:36") . "\n";
echo time2sec("2:10:08") . "\n";
echo time2sec("3:45.6") . "\n";
echo time2sec("3:40:50.67") . "\n";
echo "\n";
function time2sec( $time ) {
// INPUT: string formatted in "hh:mm:ss.ms"
// RETURN: time converted to seconds
// RETURN: -1 for invalid
$msec = 0; // mili second container
$tokens = array(); // token array
$token = ""; // token string
// Parse string
for( $i = 0 ; $i < strlen($time); $i++ ) {
$char = $time[$i];
if( $char == ":" ) { // handle h/m/s delimiter
$tokens[] = $token;
$token = "";
} else if( $char == "." ) { // handle msec delimiter
$msec = substr($time, $i);
break;
} else { // handle token
$token .= $char;
}
}
$tokens[] = $token; // add final token to token array
// Calculate seconds
$total = 0;
for( $i = count($tokens), $j = 0; $i > 0; $i--, $j++ ) {
switch($i) {
case 3: // handle hours
$total += 60 * 60 * $tokens[$j]; break;
case 2: // handle minutes
$total += 60 * $tokens[$j]; break;
case 1: // handle seconds
$total += 1 * $tokens[$j]; break;
default: // handle other situations
return(-1);
}
}
// Return result, with msec added
return( 0 + $total + $msec );
}
?>
And because everyone else had to put their one liners:
===ONE LINER VERSION===
<?php
echo t2s("1:36") . "\n";echo t2s("2:10:08") . "\n";echo t2s("3:45.6") .
"\n";echo t2s("3:40:50.67") . "\n";echo "\n";
function
t2s($t){$m=0;$ts=array();$tk="";for($i=0;$i<strlen($t);$i++){$c=$t[$i];if($c==":"){$ts[]=$tk;$tk="";}elseif($c=="."){$m=substr($t,$i);break;}else{$tk.=$c;}}$ts[]=$tk;$tt=0;for($i=count($ts),$j=0;$i>0;$i--,$j++){switch($i){case
3:$tt+=60*60*$ts[$j];break;case 2:$tt+=60*$ts[$j];break;case
1:$tt+=1*$ts[$j];break;default:return(-1);}}return(0+$tt+$m);}
?>
Kenneth
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