Binary Pattern Search in Java

 You have a given two string pattern and s(word). The first string pattern contains only the symbols 0 and 1 and the second string s contains only lowercase english letters.

Lets's say that pattern matches a substring s[1..r] or s if the following 3 conditions are met:

• they have equal length
• for each 0 in pattern the corresponding letter in the substring is a vowel
• for each 1 in pattern the corresponding letter is a consonant.

Your task is to calculate the number of substrings of s that match pattern.

Note: in this task we defines the vowels as 'a', 'e', 'i', 'o', 'u' and 'y'. All other letters are constants.

Here is the solutions:

public class Test {
    public static void main(String[] args) {
        String pattern = "010";
        String s = "amazing";
        System.out.println("Total no occurrences: " + countMatches(pattern, s));
    }

    private static int countMatches(String pattern, String s) {
        int pLen = pattern.length();
        int sLen = s.length();
        int matches = 0, fromIndex = 0;
        if( pLen != sLen) {
            String fs = s.replaceAll("[aeiouy]", "0").replaceAll("[bcdfghjklmnpqrstvwxz]", "1");
            while ((fromIndex = fs.indexOf(pattern, fromIndex)) != -1) {
                matches++;
                fromIndex++;
            }
        }
        return matches;
    }
}

Output: Total occurrences: 2

Thanks and Enjoy !!!

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