Find The Index of The First Occurrence in a String
You are given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
Example 1:
Input: haystack = "neetcodeneetcode", needle = "neet"
Output: 0Explanation: "neet" occurs at index 0 and 8.
The first occurrence is at index 0, so we return 0.
Example 2:
Input: haystack = "neetcode", needle = "codem"
Output: -1Constraints:
1 <= haystack.length, needle.length <= 10,000haystackandneedleconsist of only lowercase English characters.