Package g0201_0300.s0282_expression_add_operators

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    282 - Expression Add Operators\.

    Hard

    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.

    Note that operands in the returned expressions should not contain leading zeros.

    Example 1:

    Input: num = "123", target = 6

    Output: "1\*2\*3","1+2+3"

    Explanation: Both "1\*2\*3" and "1+2+3" evaluate to 6.

    Example 2:

    Input: num = "232", target = 8

    Output: "2\*3+2","2+3\*2"

    Explanation: Both "2\*3+2" and "2+3\*2" evaluate to 8.

    Example 3:

    Input: num = "3456237490", target = 9191

    Output: []

    Explanation: There are no expressions that can be created from "3456237490" to evaluate to 9191.

    Constraints:

    • 1 <= num.length <= 10

    • num consists of only digits.

    • <code>-2<sup>31</sup><= target <= 2<sup>31</sup> - 1</code>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final List<String> addOperators(String num, Integer target)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait