Package g1801_1900.s1896_minimum_cost_to_change_the_final_value_of_expression

Class Solution

java.lang.Object
g1801_1900.s1896_minimum_cost_to_change_the_final_value_of_expression.Solution
public class Solution extends java.lang.Object
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:

  • 1 <= expression.length <= 105
  • expression only contains '1','0','&','|','(', and ')'
  • All parentheses are properly matched.
  • There will be no empty parentheses (i.e: "()" is not a substring of expression).

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    minOperationsToFlip(java.lang.String expression)
     

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • minOperationsToFlip

      public int minOperationsToFlip(java.lang.String expression)