Codebreaker

Code breaking is all about finding the secret code.

When the game starts the player should be able to guess the secret code by providing a 4 digits number. The game finishes when the player have found the exact match for the secret code.

1. The game will return a + sign for an exact match
2. The game will return a - sign for a digit match
3. An exact match is a digit that matches a digit of the secret code both in value and in position
4. A digit match is a digit that matches a digit of the secret code in value but does not have the correct position
5. Exact matches have priority over digit matches
6. Once a digit has been used for an exact match in the secret code, it can no longer be used for any digit match

Examples:

• Secret: 1234, Proposal: 1245 ⇒ Response: ++- because two exact matches (1,2) and one digit match (4)
• Secret: 1234, Proposal: 2002 ⇒ Response: - because 2 has been used once for a digit match, cannot be re-used (rule 6)
• Secret: 1234, Proposal: 2200 ⇒ Response: +
• Secret: 1234, Proposal: 1234 ⇒ Response: ++++
• Secret: 2234, Proposal: 2234 ⇒ Response: ++++

Play the game

Requires : maven (2+), java 8

• mvn clean package
• java -jar target/codebreaker-1.0-SNAPSHOT.jar