We start by creating a database table. This is very important for web applications, because web applications can’t store state in memory, like desktop applications.
CREATE TABLE `fib` (
`n` INT NOT NULL,
`fib` INT NOT NULL,
PRIMARY KEY (`n`)
);
Now we write the PHP code. You can write the HTML form yourself, it’s not that hard.
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| <?php | |
| include "config.php"; | |
| $n = $_GET['n']; | |
| if ($n == 1) { | |
| echo "fib($n) == 1"; | |
| mysql_query("REPLACE INTO `fib` (`n`, `fib`) VALUES ('1','1')"); | |
| } | |
| else if ($n == 2) { | |
| echo "fib($n) == 1"; | |
| mysql_query("REPLACE INTO `fib` (`n`, `fib`) VALUES ('2','1')"); | |
| } | |
| else { | |
| $i = 3; | |
| while ($i <= $n) { | |
| $res = mysql_query("SELECT `fib` FROM `fib` WHERE `n` = '$i'"); | |
| if ($res) { | |
| $row = mysql_fetch_assoc($res); | |
| if (!$row['fib']) { | |
| $a = $i - 1; | |
| $res = mysql_query("SELECT `fib` FROM `fib` WHERE `n` = '$a'"); | |
| if ($res) { | |
| $row = mysql_fetch_assoc($res); | |
| $f1 = $row['fib']; | |
| } | |
| $b = $i - 2; | |
| $res = mysql_query("SELECT `fib` FROM `fib` WHERE `n` = '$b'"); | |
| if ($res) { | |
| $row = mysql_fetch_assoc($res); | |
| $f2 = $row['fib']; | |
| } | |
| $fib = $f1+$f2; | |
| mysql_query("REPLACE INTO `fib` (`n`, `fib`) VALUES ('$i','$fib')"); | |
| } | |
| } | |
| $i++; | |
| } | |
| $res = mysql_query("SELECT `fib` FROM `fib` WHERE `n` = '$n'"); | |
| if ($res) { | |
| $row = mysql_fetch_assoc($res); | |
| echo "fib($n) == " . $row['fib']; | |
| } | |
| } | |
| ?> |
Do you write code like this? I know I do.