<?php
function gdr_encode($val) {
// all characters that json encode without escaping
$chrs = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 !#$%&\'()*+,-.:;<=>?@[]^_`{|}~';
$base = strlen($chrs);
$str = '';
while ($val > 0) {
$str = $chrs[$val % $base] . $str;
$val = (int)($val / $base);
}
return $str;
}
function gdr_decode($str) {
// all characters that json encode without escaping
$chrs = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 !#$%&\'()*+,-.:;<=>?@[]^_`{|}~';
$base = strlen($chrs);
$map = array();
for ($i=0; $i<$base; $i++) {
$map[$chrs[$i]] = $i;
}
$val = 0;
for ($i=0; $i<strlen($str); $i++) {
$val *= $base;
$val += (int)$map[$str[$i]];
}
return $val;
}
function duration($val) {
if ($val < 24) {
return sprintf('%d', $val).'h';
}
if ($val < 24*10) {
return sprintf('%1.1f', $val/24).'d';
}
if ($val < 168*10) {
return sprintf('%1.1f', $val/168).'w';
}
//if ($val < 730*10) {
// return sprintf('%1.1f', $val/730).'m';
//}
return sprintf('%1.1f', $val/8760).'y';
}
function search($min, $max, $k){
if ($max < $min) {
return null;
}
$mid = round(($min+$max)/2, 0)-1;
$len = strlen(gdr_encode($mid));
if ($len == $k && strlen(gdr_encode($mid+1)) == $k+1) {
return $mid;
}
if ($len < $k) {
return search($min, $mid-1, $k);
}
return search($mid+1, $max, $k);
}
function insert(&$vals, $n) {
$min = intval('1'.str_repeat('0', $n-1));
$max = intval(str_repeat('9', $n));
$vals[] = $min;
$vals[] = $max;
$len = strlen(gdr_encode($min));
if ($len == strlen(gdr_encode($max))) {
return;
}
while ($min <= $max) {
$mid = round(($min+$max)/2, 0)-1;
$k = strlen(gdr_encode($mid));
if ($k == $len && strlen(gdr_encode($mid+1)) == $len+1) {
$vals[] = $mid;
$vals[] = $mid+1;
return;
}
if ($k <= $len) {
$max = $mid-1;
} else {
$min = $mid+1;
}
}
}
$vals = array(0);
for ($i=1; $i<8; $i++) {
insert($vals, $i);
}
$vals = array_unique($vals);
sort($vals);
//$vals = array(
// 0, 1, 99, 100, 255, 256, 999, 1000, 9999, 10000, 65535, 65536, 99999,
// 100000, 250000, 500000, 750000, 999999, 1000000, 9999999, //4294967295, 4294967296
//);
echo sprintf("%7s %7s %7s %4s\n", 'num', 'str', 'time', 'cmp');
foreach ($vals as $val) {
$enc = gdr_encode($val);
$dec = gdr_decode($enc);
if ($dec !== $val) {
echo "ERROR: $val => $enc => $dec\n";
} else {
echo sprintf("%7d %7s %7s %4d\n", $dec, "\"$enc\"", duration($val), strlen($enc)+2-strlen($val));
}
}
- Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6
- num str time cmp
0 "" 0h 1
1 "B" 1h 2
9 "J" 9h 2
10 "K" 10h 1
99 "BH" 4.1d 2
100 "BI" 4.2d 1
999 "K=" 5.9w 1
1000 "K>" 6.0w 0
9999 "BQ!" 1.1y 1
10000 "BQ#" 1.1y 0
99999 "L-`" 11.4y 0
100000 "L-{" 11.4y -1
999999 "BaNz" 114.2y 0
1000000 "BaN0" 114.2y -1
9999999 "M;r7" 1141.6y -1
- Output for 8.3.5
- Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
num str time cmp
0 "" 0h 1
1 "B" 1h 2
9 "J" 9h 2
10 "K" 10h 1
99 "BH" 4.1d 2
100 "BI" 4.2d 1
999 "K=" 5.9w 1
1000 "K>" 6.0w 0
9999 "BQ!" 1.1y 1
10000 "BQ#" 1.1y 0
99999 "L-`" 11.4y 0
100000 "L-{" 11.4y -1
999999 "BaNz" 114.2y 0
1000000 "BaN0" 114.2y -1
9999999 "M;r7" 1141.6y -1
preferences:
265.89 ms | 402 KiB | 459 Q