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
class Solution(object): def strStr(self, haystack, needle): """ :type haystack: str :type needle: str :rtype: int """ if len(haystack) < len(needle): return -1 for i in range(len(haystack) - len(needle) + 1): if haystack[i:i + len(needle)] == needle: return i return -1