leetcode 1796. Second Largest Digit in a String(python)
描述Givenanalphanumericstrings,returnthesecondlargestnumericaldigitthatappearsins,or-1ifitdoesnotexist.AnalphanumericstringisastringconsistingoflowercaseEnglishlettersanddigits.Example1:Input:s="dfa1232