rideside.net

<?php

$type = isset($_POST'sudoku_type']) ? $_POST'sudoku_type'] : 'chance';

print '<FORM ACTION=sudoku METHOD=POST>';
print ' <SELECT NAME=sudoku_type>';
IF ('chance' == $type) {
print ' <OPTION VALUE=chance SELECTED>Chance It</OPTION>';
print ' <OPTION VALUE=make>Make One (Takes ~10s.)</OPTION>';
} else {
print ' <OPTION VALUE=chance>Chance It</OPTION>';
print ' <OPTION VALUE=make SELECTED>Make One (Takes ~10s.)</OPTION>';
}
print ' </SELECT>';
print ' <INPUT TYPE=SUBMIT>';
print '</FORM><p></p><p></p>';

$stimer = explode( ' ', microtime() );
$stimer = $stimer[1] + $stimer[0];

function check(&$grid, $ii, $jj, $value)
{
if (0 == $value) {
return false;
}

for ($kk = 0; $kk < 9; $kk++) {
if ($value == $grid$ii]$kk]) {
return false;
}
}

for ($kk = 0; $kk < 9; $kk++) {
if ($value == $grid$kk]$jj]) {
return false;
}
}

$cell = array();

$ith = 3*floor(($ii) / 3);
$jth = 3*floor(($jj) / 3);

for ($i = $ith; $i < $ith + 3; $i++) {
for ($j = $jth; $j < $jth + 3; $j++) {
array_push($cell, $grid$i]$j]);
}
}

for ($i = 0; $i < sizeof($cell); $i++) {
if ($value == $cell$i]) {
return false;
}
}

return true;
}

$checks = array();
$grid = array();

for ($ii = 0; $ii < 9; $ii++) {
array_push($checks, array(0, 0, 0, 0, 0, 0, 0, 0, 0));
array_push($grid, array(0, 0, 0, 0, 0, 0, 0, 0, 0));
}

for ($ii = 0; $ii < 9; $ii++) {
$jcheck = 0;

for ($jj = 0; $jj < 9; $jj++) {
srand((double)microtime()*1000000);
$try = rand(1,9);

while (!check($grid, $ii, $jj, $try)) {
while ($checks$ii]$jj] == 8) {
$grid$ii]$jj] = 0;

if (0 == $jj) {
if (0 == $ii) {
for ($i = 0; $i < 9; $i++) {
for ($j = 0; $j < 9; $j++) {
$checks$i]$j] = 0;
}
}
} else {
$ii--;
$jj = 8;
}

} else {
$jj--;
}

$try = $grid$ii]$jj];
$try++;
}

if ($try > 8) {
$try = 1;
} else {
$try++;
}

$checks$ii]$jj]++;

if ('chance' == $type && $checks$ii]$jj] == 8) {
break 2;
}
}

$grid$ii]$jj] = $try;
}
}

$output = "<table width=320 height=180 border=1>\n";

for ($ii = 0; $ii < 9; $ii++) {
$output .= " <tr>\n";
for ($jj = 0; $jj < 9; $jj++) {
$output .= " <td align=center><font size=large>" . $grid$ii]$jj] . "</font></td>\n";
}
$output .= " </tr>\n";
}

$output .= "</table>\n";

print $output;

$etimer = explode( ' ', microtime() );
$etimer = $etimer[1] + $etimer[0];

printf( "<p></p><p></p><b>%f</b> seconds.", ($etimer-$stimer) );

if ('make' == $type) {

print '<br>';

print '<i>Optimization, anyone?</i>';

}

?>