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) { $result = ''; for($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); } return $result; } $letters = 'abcd'; echo '2 letters from 4:\n'; for($i = 0; $i < getPermCount($letters, 2); $i++) echo getPerm($letters, 2, $i).' '; echo '<br>3 letters from 4:\n'; for($i = 0; $i < getPermCount($letters, 3); $i++) echo getPerm($letters, 3, $i). " ";

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)
8.3.60.0070.01418.68
8.3.50.0120.00522.05
8.3.40.0120.00318.74
8.3.30.0200.00019.73
8.3.20.0000.00818.91
8.3.10.0000.00821.25
8.3.00.0040.00419.70
8.2.180.0100.01016.63
8.2.170.0120.00322.96
8.2.160.0110.00320.44
8.2.150.0050.00324.18
8.2.140.0080.00024.66
8.2.130.0050.00326.16
8.2.120.0080.00019.89
8.2.110.0060.00320.57
8.2.100.0080.00317.91
8.2.90.0000.00819.29
8.2.80.0000.00819.21
8.2.70.0040.00817.50
8.2.60.0030.00518.05
8.2.50.0090.00018.07
8.2.40.0030.00520.07
8.2.30.0040.00419.49
8.2.20.0050.00217.68
8.2.10.0060.00317.75
8.2.00.0050.00317.75
8.1.280.0080.00625.92
8.1.270.0030.00523.99
8.1.260.0040.00426.35
8.1.250.0050.00328.09
8.1.240.0000.01022.65
8.1.230.0050.00520.97
8.1.220.0080.00018.77
8.1.210.0040.00419.00
8.1.200.0000.00817.35
8.1.190.0040.00417.39
8.1.180.0000.00818.10
8.1.170.0030.00618.47
8.1.160.0040.00418.81
8.1.150.0040.00418.65
8.1.140.0060.00317.31
8.1.130.0030.00317.91
8.1.120.0000.00917.44
8.1.110.0050.00317.40
8.1.100.0050.00217.49
8.1.90.0000.00717.38
8.1.80.0040.00317.55
8.1.70.0000.00717.44
8.1.60.0060.00317.58
8.1.50.0080.00017.43
8.1.40.0040.00417.57
8.1.30.0040.00417.59
8.1.20.0000.00817.73
8.1.10.0000.00717.61
8.1.00.0030.00617.52
8.0.300.0070.00019.85
8.0.290.0040.00417.16
8.0.280.0000.00718.38
8.0.270.0000.00717.27
8.0.260.0030.00516.75
8.0.250.0000.00816.95
8.0.240.0040.00416.95
8.0.230.0000.00716.86
8.0.220.0030.00316.82
8.0.210.0000.00716.90
8.0.200.0030.00316.83
8.0.190.0040.00416.88
8.0.180.0030.00416.91
8.0.170.0000.00816.91
8.0.160.0040.00416.91
8.0.150.0070.00016.84
8.0.140.0050.00216.89
8.0.130.0030.00313.38
8.0.120.0060.00316.88
8.0.110.0000.00716.74
8.0.100.0040.00416.95
8.0.90.0050.00316.89
8.0.80.0100.00716.87
8.0.70.0000.00716.95
8.0.60.0000.00716.94
8.0.50.0040.00416.70
8.0.30.0110.00717.01
8.0.20.0110.01017.40
8.0.10.0000.00716.89
8.0.00.0070.01016.89
7.4.330.0030.00316.88
7.4.320.0030.00616.44
7.4.300.0000.00716.67
7.4.290.0030.00316.48
7.4.280.0030.00316.44
7.4.270.0000.00616.66
7.4.260.0000.00613.24
7.4.250.0000.00816.61
7.4.240.0000.00816.55
7.4.230.0030.00316.49
7.4.220.0040.01416.50
7.4.210.0070.00716.58
7.4.200.0070.00016.70
7.4.190.0040.00416.49
7.4.160.0100.00716.48
7.4.150.0110.00717.40
7.4.140.0080.01317.86
7.4.130.0120.00816.66
7.4.120.0110.00816.60
7.4.110.0130.01016.58
7.4.100.0110.00616.34
7.4.90.0210.00416.60
7.4.80.0210.00319.39
7.4.70.0040.01316.51
7.4.60.0150.00716.72
7.4.50.0030.00316.39
7.4.40.0120.00322.77
7.4.30.0100.01016.39
7.4.00.0100.00614.88
7.3.330.0000.00613.45
7.3.320.0030.00313.24
7.3.310.0000.00716.37
7.3.300.0060.00016.33
7.3.290.0030.01016.35
7.3.280.0100.00616.41
7.3.270.0110.00717.40
7.3.260.0090.01018.24
7.3.250.0070.01016.46
7.3.240.0100.00716.39
7.3.230.0110.00716.47
7.3.210.0040.01216.43
7.3.200.0090.01519.39
7.3.190.0130.01016.48
7.3.180.0060.01016.57
7.3.170.0100.00716.64
7.3.160.0080.00816.41
7.3.120.0060.00914.90
7.3.10.0060.00616.53
7.3.00.0060.00616.48
7.2.330.0130.00416.82
7.2.320.0200.00316.49
7.2.310.0170.00616.82
7.2.300.0120.00616.47
7.2.290.0030.01316.67
7.2.130.0060.00616.94
7.2.120.0090.00316.77
7.2.110.0000.01116.86
7.2.100.0030.00816.62
7.2.90.0030.01216.62
7.2.80.0090.00316.93
7.2.70.0040.01117.09
7.2.60.0080.00316.62
7.2.50.0080.00616.81
7.2.40.0070.00316.72
7.2.30.0080.00416.79
7.2.20.0070.00716.86
7.2.10.0040.00716.80
7.2.00.0040.00718.26
7.1.250.0040.00715.30
7.1.100.0030.01017.95
7.1.70.0070.00716.79
7.1.60.0090.01519.24
7.1.50.0100.01316.77
7.1.00.0030.04322.36
7.0.200.0030.00516.82
7.0.140.0030.07322.18
7.0.100.0330.07319.90
7.0.90.0130.07319.89
7.0.80.0000.06319.95
7.0.70.0130.06319.89
7.0.60.0300.08019.99
7.0.50.0100.08020.24
7.0.40.0070.07720.03
7.0.30.0100.08320.01
7.0.20.0070.08320.04
7.0.10.0100.08020.05
7.0.00.0100.05720.04
5.6.280.0000.07721.08
5.6.250.0070.06020.73
5.6.240.0100.06320.47
5.6.230.0130.07320.46
5.6.220.0030.09320.45
5.6.210.0070.08320.45
5.6.200.0100.07721.07
5.6.190.0000.09321.00
5.6.180.0100.08320.99
5.6.170.0070.08020.89
5.6.160.0170.04720.97
5.6.150.0100.07721.09
5.6.140.0070.07721.00
5.6.130.0100.08020.98
5.6.120.0030.06721.04
5.6.110.0000.05720.96
5.6.100.0130.07321.02
5.6.90.0030.08720.95
5.6.80.0100.07720.42
5.6.70.0030.04720.36
5.6.60.0130.06720.36
5.6.50.0000.05320.38
5.6.40.0200.04020.42
5.6.30.0000.06020.46
5.6.20.0100.08020.33
5.6.10.0130.05720.45
5.6.00.0030.05320.38
5.5.380.0130.08020.48
5.5.370.0070.08020.36
5.5.360.0070.08020.34
5.5.350.0070.08020.28
5.5.340.0070.07020.79
5.5.330.0070.05720.87
5.5.320.0070.07320.84
5.5.310.0230.05020.86
5.5.300.0100.08320.76
5.5.290.0000.09720.76
5.5.280.0130.07320.79
5.5.270.0170.07320.81
5.5.260.0030.08720.75
5.5.250.0100.07020.70
5.5.240.0100.07320.08
5.5.230.0100.04719.97
5.5.220.0030.08020.20
5.5.210.0030.04020.12
5.5.200.0100.08020.21
5.5.190.0100.07020.11
5.5.180.0070.05020.10
5.5.160.0030.05020.07
5.5.150.0170.04720.08
5.5.140.0030.05020.18
5.5.130.0230.06320.18
5.5.120.0030.07320.08
5.5.110.0100.06720.20
5.5.100.0070.07020.00
5.5.90.0030.08720.02
5.5.80.0030.05020.08
5.5.70.0000.07719.93
5.5.60.0070.04020.02
5.5.50.0100.07720.10
5.5.40.0030.08020.09
5.5.30.0070.08020.11
5.5.20.0200.07719.98
5.5.10.0070.07720.01
5.5.00.0070.07719.99
5.4.450.0030.08019.52
5.4.440.0070.07719.57
5.4.430.0100.05719.32
5.4.420.0070.07719.46
5.4.410.0070.07719.25
5.4.400.0130.04018.91
5.4.390.0170.06319.13
5.4.380.0070.07719.18
5.4.370.0030.07319.09
5.4.360.0100.06718.88
5.4.350.0070.05719.11
5.4.340.0000.05319.14
5.4.320.0030.07719.12
5.4.310.0030.04319.21
5.4.300.0070.04318.91
5.4.290.0130.06319.13
5.4.280.0100.07719.16
5.4.270.0070.07019.13
5.4.260.0070.07718.84
5.4.250.0030.04318.94
5.4.240.0170.05019.09
5.4.230.0130.06719.04
5.4.220.0000.07719.04
5.4.210.0030.08019.12
5.4.200.0070.06719.21
5.4.190.0100.06719.17
5.4.180.0100.07019.16
5.4.170.0070.04319.09
5.4.160.0200.06018.94
5.4.150.0130.06318.83
5.4.140.0070.04316.44
5.4.130.0070.03316.42
5.4.120.0030.03716.42
5.4.110.0000.04716.42
5.4.100.0000.04016.39
5.4.90.0070.03316.53
5.4.80.0070.03316.47
5.4.70.0030.04716.49
5.4.60.0070.03316.54
5.4.50.0100.03016.51
5.4.40.0100.03316.46
5.4.30.0070.03316.39
5.4.20.0000.04016.41
5.4.10.0070.03316.48
5.4.00.0030.03715.85
5.3.290.0070.07014.79
5.3.280.0030.08014.55
5.3.270.0030.07714.73
5.3.260.0100.07314.67
5.3.250.0200.04314.71
5.3.240.0070.03714.64
5.3.230.0170.03314.70
5.3.220.0070.04314.70
5.3.210.0030.04014.56
5.3.200.0000.04014.61
5.3.190.0000.04014.51
5.3.180.0030.03714.59
5.3.170.0100.03314.59
5.3.160.0030.03714.63
5.3.150.0000.04014.55
5.3.140.0030.03714.62
5.3.130.0000.04014.61
5.3.120.0030.04014.57
5.3.110.0000.04014.62
5.3.100.0030.03714.18
5.3.90.0000.04014.05
5.3.80.0030.03714.04
5.3.70.0100.03714.09
5.3.60.0030.04713.95
5.3.50.0070.04313.84
5.3.40.0000.04013.93
5.3.30.0000.03713.91
5.3.20.0030.04713.76
5.3.10.0070.03013.67
5.3.00.0030.03313.57
5.2.170.0000.04011.13
5.2.160.0030.02711.13
5.2.150.0030.03011.22
5.2.140.0000.03311.07
5.2.130.0070.02711.21
5.2.120.0030.03311.13
5.2.110.0000.03011.09
5.2.100.0030.02711.16
5.2.90.0070.02311.18
5.2.80.0030.02711.11
5.2.70.0000.03011.17
5.2.60.0000.03011.12
5.2.50.0000.04311.09
5.2.40.0000.03010.92
5.2.30.0000.03011.12
5.2.20.0000.03011.11
5.2.10.0000.03010.88
5.2.00.0030.02710.82
5.1.60.0030.02310.01
5.1.50.0030.02310.06
5.1.40.0030.0239.98
5.1.30.0000.02710.21
5.1.20.0000.02710.47
5.1.10.0030.02010.08
5.1.00.0000.0279.92
5.0.50.0000.0208.61
5.0.40.0000.0208.45
5.0.30.0030.0308.22
5.0.20.0000.0208.28
5.0.10.0030.0208.18
5.0.00.0000.0308.27
4.4.90.0000.0178.08
4.4.80.0000.0208.08
4.4.70.0030.0138.08
4.4.60.0030.0138.08
4.4.50.0000.0178.08
4.4.40.0030.0238.08
4.4.30.0000.0178.08
4.4.20.0000.0138.08
4.4.10.0000.0138.08
4.4.00.0000.0238.08
4.3.110.0000.0178.08
4.3.100.0070.0108.08
4.3.90.0030.0138.08
4.3.80.0000.0378.08
4.3.70.0000.0138.08
4.3.60.0000.0178.08
4.3.50.0030.0108.08
4.3.40.0000.0238.08
4.3.30.0000.0178.08
4.3.20.0030.0138.08
4.3.10.0070.0108.08
4.3.00.0000.0178.08

preferences:
44.97 ms | 401 KiB | 5 Q