- Implement strStr()
def strStr(self, haystack, needle):
"""
:type haystack: str
:type needle: str
:rtype: int
"""
h = len(haystack)
n = len(needle)
for i in range(h - n + 1):
if haystack[i:i + n] == needle:
return i
return -1
返回needle字符串在haystack字符串出现的第一个位置
