Given a string num that contains only digits and an integer target, return all possibilities to add the binary operators '+', '-', or '*' between the digits of num so that the resultant expression evaluates to the target value.
Example 1:
Input: num = "123", target = 6 Output: ["1*2*3","1+2+3"]
Example 2:
Input: num = "232", target = 8 Output: ["2*3+2","2+3*2"]
Example 3:
Input: num = "105", target = 5 Output: ["1*0+5","10-5"]
Example 4:
Input: num = "00", target = 0 Output: ["0*0","0+0","0-0"]
Example 5:
Input: num = "3456237490", target = 9191 Output: []
Constraints:
1 <= num.length <= 10numconsists of only digits.-231 <= target <= 231 - 1