Question description literally sucks!!! took me an hour guessing what am i supposed to do!
so here is the deal... computer has saved a "single" number that we are supposed to find by guessing. and the code xAyB tells us how much right we guessed. x tells us about exact digit matches with same position and y tells us about the digits which are there in savd number but we guessed in diff. position. so finally we have to get x=6 . so go hit n trial all the way. hope this helps!

LIFE IS LIKE A BOX OF CHOCOLATES. YOU NEVER KNOW WHAT YOU'RE GONNA GET.
for a good guess put all number same
to know which digit is really in string

being decoder :D

Question explanation:
Goal- To get 6AxB where x depends on how many of a certain digit are repeated in the target number. For example if the target number is 111111, and you guessed 123456, then you would get 1A5B. 1A because the first digit-(1) in the guess is at the correct location. 5B is calculated by looping through the digits of the target number and checking for each digit if it is present in the guess at a different position. So, in the 2nd iteration of this loop, the '1' in 123456 is in a different position than the 2nd '1' in the target-(1->'1'<-1111). Therefore, B will increase by 1. So, for each '1' in 111111 except the first, B would increase by 1, giving 5B. Hope this helps!

a bug
how is this possible
The number you guessed just now was 111111.
And the result is 1A5B.
arranging them is the same number