L28 Implement strStr()

Problem:

Implement strStr()

Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.

Example 1:

Input: haystack = "hello", needle = "ll"
Output: 2

Example 2:

Input: haystack = "aaaaa", needle = "bba"
Output: -1

Solution:

public int strStr(String haystack, String needle) {
    for(int i = 0; i <= haystack.length(); i++){
        for(int j = 0; j <= needle.length(); j++){
            if(j == needle.length()) return i;
            if(i + j == haystack.length()) return -1;
            if(needle.charAt(j) != haystack.charAt(i+j)) break;
        }
    }
    return -1;
}