Hi. I have a string of digits in the range 0000 - 9999.
From these digits a 4 digit code is calculated.
I am interested in finding the algorithm of calculation and then the source of such a program in python, php or other language.
Example serial, code
0000,1111
0001,1121
0002,1131
0003,1141
0004,1151
0005,1161
0006,1131
0007,1131
0008,1111
0022,3131
0023,3141
5925,3662
5926,3632
5927,3632
5928,3612
5929,3622
5930,4612
Request deadline, price.