Code Breaker

User makes a secret code and program tries to guess.

The documented results are produced from revision 6b74221.

Donald Knuth 5-Guess Algorithm

Donald Knuth algorithm always finds the secret code in at most 5 attempts.

It is the best algorithm among the 3.

Test Case 1

Secret Code: Red Purple Yellow Orange

Number of Attempts	Attempt	Hints
1	Green Green Red Red	Black: 0, White: 1
2	Blue Purple Green Yellow	Black: 1, White: 1
3	Red Purple Orange Blue	Black: 2, White: 1
4	Red Purple Blue Purple	Black: 2, White: 0
5	Red Purple Yellow Orange	Black: 4, White: 0

Test Case 2

Secret Code: Yellow Purple Green Blue

Number of Attempts	Attempt	Hints
1	Green Green Red Red	Black: 0, White: 1
2	Red Blue blue Purple	Black: 0, White: 2
3	Orange Red Orange Black	Black: 1, White: 0
4	Purple Purple Green Blue	Black: 3, White: 0
5	Yellow Purple Green Blue	Black: 4, White: 0

Medium Algorithm

Medium algorithm finds the secret code in 7 attempts in both tests.

It’s slightly less optimal than Donald Knuth’s algorithm.

Test Case 3

Secret Code: Red Purple Yellow Orange

Number of Attempts	Attempt	Hints
1	Green Green Green Green	Black: 0, White: 0
2	Blue Blue Blue Blue	Black: 0, White: 0
3	Yellow Yellow Yellow Yellow	Black: 1, White: 0
4	Purple Yellow Purple Purple	Black: 0, White: 2
5	Yellow Purple Orange Red	Black: 1, White: 3
6	Orange Purple Red Yellow	Black: 1, White: 3
7	Red Purple Yellow Orange	Black: 4, White: 0

Test Case 4

Secret Code: Yellow Purple Green Blue

Number of Attempts	Attempt	Hints
1	Green Green Green Green	Black: 1, White: 0
2	Blue Blue Blue Blue	Black: 1, White: 0
3	Yellow Yellow Yellow Yellow	Black: 1, White: 0
4	Yellow Blue Purple Green	Black: 1, White: 3
5	Purple Yellow Blue Green	Black: 0, White: 4
6	Green Blue Yellow Purple	Black: 0, White: 4
7	Yellow Purple Green Blue	Black: 4, White: 0

Basic Algorithm

Basic algorithm would almost never find the secret code (did not find the secret code in this case).

This is intended behavior.

Test Case 5

Secret Code: Red Purple Yellow Orange

Number of Attempts	Attempt	Hints
1	Purple Green Green Blue	Black: 0, White: 1
2	Green Orange Red Blue	Black: 0, White: 2
3	Red Orange Purple Red	Black: 1, White: 2
4	Yellow Green Yellow Red	Black: 1, White: 1
5	Orange Green Yellow Yellow	Black: 1, White: 1
6	Orange Red Blue Purple	Black: 0, White: 3
7	Green Purple Blue Purple	Black: 1, White: 0
8	Green Green Purple Orange	Black: 1, White: 1
9	Orange Green Yellow Purple	Black: 1, White: 2
10	Yellow Blue Blue Blue	Black: 0, White: 1

Test Case 6

Secret Code: Yellow Purple Green Blue

Number of Attempts	Attempt	Hints
1	Blue Orange Orange Blue	Black: 1, White: 0
2	Purple Green Red Purple	Black: 0, White: 2
3	Blue Red Blue Orange	Black: 0, White: 1
4	Blue Green Red Red	Black: 0, White: 2
5	Orange Blue Yellow Red	Black: 0, White: 2
6	Orange Green Red Green	Black: 0, White: 1
7	Orange Green Purple Red	Black: 0, White: 2
8	Green yellow Red Green	Black: 0, White: 2
9	Blue Blue Green Orange	Black: 1, White: 1
10	Purple Red Purple Green	Black: 0, White: 2