28-find-the-index-of-the-first-occurrence-in-a-string

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 = “sadbutsad”, needle = “sad” Output: 0 Explanation: “sad” occurs at index 0 and 6. The first occurrence is at index 0, so we return 0. Example 2:

Input: haystack = “leetcode”, needle = “leeto” Output: -1 Explanation: “leeto” did not occur in “leetcode”, so we return -1.

My solution：

Use List.find()

```python class Solution(object): def strStr(self, haystack, needle): “”” :type haystack: str :type needle: str :rtype: int “”” return haystack.find(needle)

Time Complexity: O(n) Space Complexity: O(1)