挑战24点-益智休闲

24 points is a kind of puzzle and entertainment mini game to be played.
The rules are as follows: use addition, subtraction, multiplication, division and parentheses to obtain 24. Each card must be used once, but cannot be used repeatedly.
App Provide Functions:
1. random number to calculate 24
2. get hint
3. choose challenge degree
4. check challenge record, share to others
5. custom card image