1 class Solution(object):
2 def strStr(self, haystack, needle):
3 """
4 :type haystack: str
5 :type needle: str
6 :rtype: int
7 """
8 # 若子串为空
9 if needle == "":
10 return 0
11 # 若两串相同
12 if len(haystack) == len(needle):
13 if haystack == needle:
14 return 0
15 else:
16 return -1
17 # 获取两个串的长度
18 size1 = len(haystack)
19 size2 = len(needle)
20 print("两个串的长度分别是：", size1, size2)
21 for index in range(size1):
22 ans = index
23 j = 0
24 while j < size2 and ans < size1 and haystack[ans] == needle[j]:
25 j += 1
26 ans += 1
27 if j == size2:
28 return index
29 return -1 if needle else 0
30
31 if __name__ == '__main__':
32 solution = Solution()
33 print(solution.strStr("aaa", "a"))
34 print(solution.strStr("hello", "lo"))
35 print(solution.strStr("hello", "el"))
