class Solution(object):

     def strStr(self, haystack, needle):

         """

         :type haystack: str

         :type needle: str

         :rtype: int

         """

         return haystack.find(needle)

class Solution(object):

    def strStr(self, haystack, needle):

        """

        :type haystack: str

        :type needle: str

        :rtype: int

        """

        result = -1

        l_needle = len(needle)

        l_haystack = len(haystack)

        if l_needle == 0 and l_haystack == 0:

            return 0

        if l_haystack == 0 and l_needle!=0:

            return result

        if l_needle == 0 :

            return 0

        for index in range(l_haystack):

            if l_haystack - index  >= l_needle and needle == haystack[index:index+l_needle]:

                result = index

                break

        return result 

class Solution(object):

    def strStr(self, haystack, needle):

        """

        :type haystack: str

        :type needle: str

        :rtype: int

        """

        result = -1

        l_needle = len(needle)

        l_haystack = len(haystack)

        if l_needle == 0 and l_haystack == 0:

            return 0

        if l_haystack == 0 and l_needle!=0:

            return result

        if l_needle == 0 :

            return 0

        if l_needle>l_haystack:

            return result

        hash_needle=hash(needle)

        list_haystack=[]

        for index in range(l_haystack):

            if index<=(l_haystack-l_needle):

                list_haystack.append(hash(haystack[index:index+l_needle]))

        result=list_haystack.index(hash_needle) if hash_needle in  list_haystack else -1

        return result