输入一个长字符串和一个短字符串，统计在长字符串中短字符串出现的次数，返回长字符串中首次出现短字符串的位置。如addabdabd和bd,出现次数为2，位置值为5-Enter a long string and a short string, long string of statistics in the number of occurrences in the short string and returns the first occurrence of a short length of s