leetcode28 Implement strStr()
1 """ 2 Implement strStr(). 3 Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 4 Example 1: 5 Input: haystack = "hello", needle = "ll" 6 Output: 2 7 Example 2: 8 Input: haystack = "aaaaa", needle = "bba" 9 Output: -1 10 """ 11 """ 12 用切片的方法匹配字符 13 """ 14 class Solution: 15 def strStr(self, haystack, needle): 16 for i in range(len(haystack) - len(needle)+1):#bug此处不加1,input如果为两个空字符串,无法输出i 17 if needle == haystack[i:i+len(needle)]: 18 return i 19 return -1