Leetcode - Implement strStr().py

### Implement strStr().

### 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.

### Clarification:

### What should we return when needle is an empty string? This is a great question to ask during an interview.

### For the purpose of this problem, we will return 0 when needle is an empty string. This is consistent to C's strstr() and Java's indexOf().

 

### Example 1:
### Input: haystack = "hello", needle = "ll"
### Output: 2

### Example 2:
### Input: haystack = "aaaaa", needle = "bba"
### Output: -1
 
### Constraints:
### 1 <= haystack.length, needle.length <= 104
### haystack and needle consist of only lowercase English characters.

class Solution:
    def strStr(self, haystack: str, needle: str) -> int:
        if needle in haystack:
            return haystack.find(needle)
        else:
            return -1
          
# Runtime: 32 ms, faster than 86.53% of Python3 online submissions for Implement strStr().
# Memory Usage: 13.9 MB, less than 68.97% of Python3 online submissions for Implement strStr().