Expression Add Operators
Given a string num that contains only digits and an integer target, return all possibilities to insert the binary operators '+', '-', and/or '*' between the digits of num so that the resultant expression evaluates to the target value.
Operands in the returned expressions should not contain leading zeros.
Note that a number can contain multiple digits.
Example 1
Input
num = "123", target = 6Output
["1*2*3","1+2+3"]Both "1*2*3" and "1+2+3" evaluate to 6.
Example 2
Input
num = "232", target = 8Output
["2*3+2","2+3*2"]Both "2*3+2" and "2+3*2" evaluate to 8.
Constraints
- 1 <= num.length <= 10
- num consists of only digits.
- -2^31 <= target <= 2^31 - 1