猜数字: https://leetcode-cn.com/problems/bulls-and-cows/
https://en.wikipedia.org/wiki/Bulls_and_Cows

Guess the 4 distict number:

Basic usage:

• Enter your guess (4 distinct digits) in the textbox
• Click submit
  • It will show correct position and number (?A?B)
  • It also shows remain possible candidates count
  • If your hover cursor over the candidate count value, it shows the first 10 candidate values
• Click the new game if your want start a new game
• Click the hint will output a guess with one of the algorithm:
  • min-largest-group-size (Knuth, 1977)
  • min-group-expect-size (Irving, 1978)
  • max-group-entropy

Test the algorithm:

1. Choose 4 distinct digits. For example `2468`
2. Click hint, it will display a result in the textbox. Let's say it's `0123`
3. Feedback correct positions and numbers in the textbox: `0123 0A1B`
4. Click submit
5. The algorithm may supply a new guess: `1456`, goto step 3.