def strStr_brute_force(self, haystack, needle):
        """
        Algorithm:
        two pointers

        :param haystack: str
        :param needle: str
        :return: str or None
        """
        l_hay = len(haystack)
        l_ndl = len(needle)
        for i in xrange(l_hay-l_ndl+1):  # i+l_ndl <= l_hay
            if haystack[i:i+l_ndl]==needle:
                return haystack[i:]
        return None
dataset/ETHPy150Open algorhythms/LeetCode/028 Implement strStr().py/Solution.strStr_brute_force/original