Week 1/20/19 of Cassido's newsletter

repeatedSubString.java

import java.util.regex.*;

/**
 * Created by kylel95 on 1/22/19.
 */
public class repeatedSubString {
    public static void main(String [] args){
        System.out.println(repeat("pi", "pipipipi"));
        System.out.println(repeat("danger", "cassidy"));

    }

    /**
     * Given two strings x and y, write a function that returns how many times x can be repeated to generate y.
     * If y cannot be generated by repeating x, return -1.
     * @param x needle, string that is possible in y
     * @param y haystack, full string
     * @return how many times x appears in y
     */
    public static int repeat(String x, String y){
        Pattern p = Pattern.compile(x);
        Matcher m = p.matcher(y);
        int count = 0;
        if(m.find()){
            count++;
            while (m.find()) {
                count++;
            }
            return count;
        }
        else{
            return -1;
        }

    }
}

repeat("foo", "1foo2foo3foo4") is 3 not -1