679 - 24 Game\.

Hard

You are given an integer array cards of length 4. You have four cards, each containing a number in the range [1, 9]. You should arrange the numbers on these cards in a mathematical expression using the operators ['+', '-', '*', '/'] and the parentheses '(' and ')' to get the value 24.

You are restricted with the following rules:

• The division operator '/' represents real division, not integer division.

• Every operation done is between two numbers. In particular, we cannot use '-' as a unary operator.

• You cannot concatenate numbers together

Return true if you can get such expression that evaluates to 24, and false otherwise.

Example 1:

Input: cards = 4,1,8,7

Output: true

Explanation: (8-4) \* (7-1) = 24

Example 2:

Input: cards = 1,2,1,2

Output: false

Constraints:

• cards.length == 4

• 1 <= cards[i] <= 9