I am stuck on this problem for quite a while, it is basically reverse engineering bulls and cow game.
Read more here: http://rosettacode.org/wiki/Bulls_and_cows
I am not able to develop a logic for the problem given below, if you can think of a solving approach please comment the same.
Problem Statement:
Given few clue words(of form ABCD/DBCA etc) and the number of cows and bulls for each word,program
should be able to work out the actual word by evaluating the given clue words and generate the output secret word.
TEST CASES:
Input:
4
DBCC 0 2
CDAB 2 1
CAAD 1 2
CDDA 2 0
Output:
BDAA
The idea is to reduce the space of possible solutions. Before you start, all 4^4 combinations are possible. After you read the first clue [DBCC 0 2 ], you can eliminate a number of possible solutions, in this particular example you can eliminate all states which have a D in the first place, all which have a B in the second place and so on. Just eliminate all possible solutions which do not “fit” the current clue.
Do this with each clue, until only one solution is left. Another interesting problem of course is how to generate good clue patterns.