3v4l.org

run code in 300+ PHP versions simultaneously
<?php // Returns the total number of $count-length strings generatable from $letters. function getPermCount($letters, $count) { $result = 1; // k characters from a set of n has n!/(n-k)! possible combinations for($i = strlen($letters) - $count + 1; $i <= strlen($letters); $i++) { $result *= $i; } return $result; } // Decodes $index to a $count-length string from $letters, no repeat chars. function getPerm($letters, $count, $index) { $result = array(); for($i = 0; $i < $count; $i++) { $pos = $index % strlen($letters); $result[] = $letters[$pos]; $index = ($index-$pos)/strlen($letters); $letters = substr($letters, 0, $pos) . substr($letters, $pos+1); } sort($result); $result = array_unique($result, SORT_REGULAR); return implode("", $result); } $r = array(); //$letters = 'abcdefghijklm'; $letters = 'abcdefgh'; $len = strlen($letters); for ($c = 1; $c <= $len; $c++) { for($i = 0; $i < getPermCount($letters, $c); $i++) $r[] = getPerm($letters, $c, $i); } //print_r(array_unique($r, SORT_REGULAR)); $r = array_unique($r, SORT_REGULAR); print_r(count($r));

Here you find the average performance (time & memory) of each version. A grayed out version indicates it didn't complete successfully (based on exit-code).

VersionSystem time (s)User time (s)Memory (MiB)
8.3.70.0200.27827.84
8.3.60.0070.29130.36
8.3.50.0230.32927.80
8.3.40.0170.28629.79
8.3.30.0300.28131.43
8.3.20.0070.15229.71
8.3.10.0000.15433.24
8.3.00.0070.15335.77
8.2.180.0130.29827.91
8.2.170.0130.28929.88
8.2.160.0130.28131.77
8.2.150.0100.14630.14
8.2.140.0100.15331.65
8.2.130.0030.15434.42
8.2.120.0070.15332.08
8.2.110.0070.20934.38
8.2.100.0130.20929.03
8.2.90.0030.21430.42
8.2.80.0070.20630.46
8.2.70.0230.24128.63
8.2.60.0070.21629.15
8.2.50.0100.22628.88
8.2.40.0130.20429.72
8.2.30.0100.20230.67
8.2.20.0100.20928.86
8.2.10.0130.20729.02
8.2.00.0100.20329.00
8.1.280.0300.30532.16
8.1.270.0130.13936.73
8.1.260.0100.14234.87
8.1.250.0070.14039.41
8.1.240.0170.22837.00
8.1.230.0130.20135.43
8.1.220.0160.20432.21
8.1.210.0100.18933.40
8.1.200.0100.20531.86
8.1.190.0130.20032.05
8.1.180.0100.20031.96
8.1.170.0030.20233.07
8.1.160.0200.20433.41
8.1.150.0160.19533.23
8.1.140.0100.20232.05
8.1.130.0100.19432.48
8.1.120.0200.24131.97
8.1.110.0070.20032.11
8.1.100.0170.19931.96
8.1.90.0100.20732.05
8.1.80.0100.19531.95
8.1.70.0100.20131.95
8.1.60.0070.21732.14
8.1.50.0170.20431.96
8.1.40.0100.21432.04
8.1.30.0030.21932.09
8.1.20.0100.21332.08
8.1.10.0030.21732.07
8.1.00.0070.21632.07
8.0.300.0070.19934.22
8.0.290.0200.18931.44
8.0.280.0030.21132.93
8.0.270.0070.19931.73
8.0.260.0100.20031.25
8.0.250.0100.20531.38
8.0.240.0100.20831.34
8.0.230.0030.20831.47
8.0.220.0100.20631.34
8.0.210.0030.21331.27
8.0.200.0070.20331.32
8.0.190.0030.22131.24
8.0.180.0130.25531.30
8.0.170.0030.22531.33
8.0.160.0070.21531.32
8.0.150.0170.21131.22
8.0.140.0070.21531.37
8.0.130.0030.21927.82
8.0.120.0070.22131.30
8.0.110.0100.21531.42
8.0.100.0070.21431.42
8.0.90.0030.22031.20
8.0.80.0230.36431.35
8.0.70.0030.24031.30
8.0.60.0030.22131.31
8.0.50.0030.21831.16
8.0.30.0160.33931.62
8.0.20.0260.37531.66
8.0.10.0100.21231.50
8.0.00.0330.45331.04
7.4.330.0000.21032.67
7.4.320.0100.21630.81
7.4.300.0100.21531.00
7.4.290.0030.24131.00
7.4.280.0030.23631.04
7.4.270.0100.22631.00
7.4.260.0130.22227.75
7.4.250.0000.25530.98
7.4.240.0000.23731.03
7.4.230.0100.22931.09
7.4.220.0330.52830.92
7.4.210.0250.37031.01
7.4.200.0030.23730.92
7.4.190.0070.23430.88
7.4.160.0170.36731.14
7.4.150.0430.50831.05
7.4.140.0260.36230.97
7.4.130.0330.40530.87
7.4.120.0200.36531.00
7.4.110.0300.37631.19
7.4.100.0230.37231.09
7.4.90.0260.40431.00
7.4.80.0320.45131.07
7.4.70.0490.42030.84
7.4.60.0130.35131.06
7.4.50.0000.20830.93
7.4.40.0200.40230.73
7.4.30.0130.48430.77
7.3.330.0070.24027.77
7.3.320.0100.24127.91
7.3.310.0130.23730.82
7.3.300.0070.24330.75
7.3.290.0230.36630.82
7.3.280.0270.41930.77
7.3.270.0230.36931.04
7.3.260.0720.44830.98
7.3.250.0200.39230.77
7.3.240.0230.37630.91
7.3.230.0300.36631.03
7.3.210.0260.38831.05
7.3.200.0250.66430.87
7.3.190.0390.70530.75
7.3.180.0130.38630.68
7.3.170.0360.64830.87
7.3.160.0160.37430.94
7.2.330.0510.39631.06
7.2.320.0290.62831.21
7.2.310.0190.52131.37
7.2.300.0300.40231.18
7.2.290.0300.38531.25
7.2.90.7710.50629.09
7.2.80.7200.38828.92
7.2.71.1230.38229.54
7.2.60.8750.39929.27
7.2.50.8810.42629.23
7.2.40.8650.40625.28
7.2.30.9230.40929.21
7.2.21.2740.35327.42
7.1.210.6250.51728.16
7.1.200.6230.41928.11
7.1.190.8950.46328.25
7.1.180.6890.39827.92
7.1.171.1770.42827.90
7.1.160.9730.53923.01
7.1.151.0310.42723.14
7.1.141.0750.34128.59
7.0.310.3930.64327.88
7.0.301.1430.37122.39
7.0.291.1280.41922.62
7.0.281.2050.38422.25

preferences:
62.51 ms | 401 KiB | 5 Q