Class Solution

  • All Implemented Interfaces:

    
    public final class Solution
    
                        

    1896 - Minimum Cost to Change the Final Value of Expression.

    Hard

    You are given a valid boolean expression as a string expression consisting of the characters '1','0','&' (bitwise AND operator),'|' (bitwise OR operator),'(', and ')'.

    • For example, "()1|1" and "(1)&()" are not valid while "1", "(((1))|(0))", and "1|(0&(1))" are valid expressions.

    Return the minimum cost to change the final value of the expression.

    • For example, if expression = "1|1|(0&0)&1", its value is 1|1|(0&0)&1 = 1|1|0&1 = 1|0&1 = 1&1 = 1. We want to apply operations so that the new expression evaluates to 0.

    The cost of changing the final value of an expression is the number of operations performed on the expression. The types of operations are described as follows:

    • Turn a '1' into a '0'.

    • Turn a '0' into a '1'.

    • Turn a '&' into a '|'.

    • Turn a '|' into a '&'.

    Note: '&' does not take precedence over '|' in the order of calculation. Evaluate parentheses first , then in left-to-right order.

    Example 1:

    Input: expression = "1&(0|1)"

    Output: 1

    Explanation: We can turn "1&(0|1)" into "1&(0&1)" by changing the '|' to a '&' using 1 operation.

    The new expression evaluates to 0.

    Example 2:

    Input: expression = "(0&0)&(0&0&0)"

    Output: 3

    Explanation: We can turn "(0&0)&(0&0&0)" into "(0|1)|(0&0&0)" using 3 operations.

    The new expression evaluates to 1.

    Example 3:

    Input: expression = "(0|(1|0&1))"

    Output: 1

    Explanation: We can turn "(0|(1|0&1))" into "(0|(0|0&1))" using 1 operation.

    The new expression evaluates to 0.

    Constraints:

    • <code>1 <= expression.length <= 10<sup>5</sup></code>

    • expression only contains '1','0','&amp;','|','(', and ')'

    • All parentheses are properly matched.

    • There will be no empty parentheses (i.e: "()" is not a substring of expression).

    • 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 Integer minOperationsToFlip(String expression)
      • Methods inherited from class java.lang.Object

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