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@NogDogOct 12.2010 — #You could use the [url=http://www.php.net/manual/en/book.bc.php]BCMath functions[/url] , or the PEAR [url=http://pear.php.net/package/Math_BigInteger]Math_BigInteger package[/url] .@NogDogOct 13.2010 — #
And be prepared to wait awhile, and probably have to use set_time_limit() to allow it to run long enough. (120 seconds was not enough on my PC.) ?@NogDogOct 14.2010 — #You can set it to zero (0), which means no time limit. However, before doing that, try setting the maximum for $i in the loop condition to a much smaller number to test your code before letting it loose for 4 million iterations so you can find out if the code is reasonable. If it takes 1/1000th of a second per iteration (purely hypothetically, maybe more, maybe less), you'll need at least 4000 seconds -- a bit over an hour -- for it to run.
interger problem
Hi all.
I am trying to solve a problem from project euler, for the purpose of learning ? I’m not asking here for the answer or logic, I got the latter but it seems that I have a problem in outputting the integer since it exceeds the limit of variable limit in PHP (as I know).
[code=php]
<?php
$a = 0;
$b = 1;
$c = 0;
$even_count = 0;
for( $i = 0 ; $i < 4000000 ; $i++ ) {
$c = $a + $b;
$a = $b;
$b = $c;
if( $c % 2 == 0 ) {
$even_count += $c;
}
}
echo “Sum of all even-valued terms: ” . $even_count;
?>
The code is all about the sum of even numbers in the fibbonaci sequence which do not exceed four million.
Whenver I run the program the output as expected is
[CODE]Sum of all even-valued terms: INF
I can’t figure out how to output such big number. Any help? Thanks.
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@NogDogOct 12.2010 — #You could use the 0
@NogDogOct 13.2010 — #[code=php]
$a = 0;
$b = 1;
$c = 0;
$even_count = 0;
for ($i = 0; $i < 4000000; $i++) {
$c = bcadd($a, $b);
$a = $b;
$b = $c;
if (bcmod($c, 2) == 0) {
$even_count = bcadd($even_count, $c);
}
}
echo "Sum of all even-valued terms: " . $even_count;
[/code]And be prepared to wait awhile, and probably have to use set_time_limit() to allow it to run long enough. (120 seconds was not enough on my PC.) ?
0
@NogDogOct 14.2010 — #