Problem Statement

A string, s , is composed of the letters a , b , c , and d . The string is said to be balanced if both of the following conditions are satisfied: The summed number of a 's and c 's is even. The summed number of b 's and d 's is even. For example, the strings 'abcd' ( a count + c count = 1 + 1 = 2, even, b count + d count = 1 + 1 = 2, even) is balanced , but 'abc' and 'bcd' are not. Complete the code in the editor below by filling in the blank (i.e., ______) with a RegEx that only matches balanced strings. Constraints Each character s[i] ∈ {abcd} . Input Format for Custom Testing import java.io.*;... public class Solution { public static void main(String args[]) { Regex_Test tester = new Regex_Test(); tester.checker("______"); Use \\ instead of using \ } } class Regex_Test { ...