class Solution {
    public int strStr(String haystack, String needle) {
        if (haystack.length() < needle.length()) return -1;

        for (int i = 0; i <= haystack.length() - needle.length(); i++){
            int j = 0;
            for (; j < needle.length(); j++){
                if (haystack.charAt(i + j) != needle.charAt(j)) break;
            }

            if (j == needle.length()) {
                //System.out.println("c: " + haystack.charAt(i) + " i: " + i);
                return i;
            }
        }

        return -1;
    }
}