Given a string s formed by digits (‘0’ – ‘9’) and ‘#’ . We want to map s to English lowercase characters as follows:

  • Characters (‘a’ to ‘i’) are represented by (‘1’ to ‘9’) respectively.
  • Characters (‘j’ to ‘z’) are represented by (’10#’ to ’26#’) respectively. 
    Return the string formed after mapping.

It’s guaranteed that a unique mapping will always exist.

Example 1:
Input: s = "10#11#12"
Output: "jkab"
Explanation: "j" -> "10#" , "k" -> "11#" , "a" -> "1" , "b" -> "2".

Example 2:
Input: s = "1326#"
Output: "acz"

Example 3:
Input: s = "25#"
Output: "y"

Example 4:
Input: s = "12345678910#11#12#13#14#15#16#17#18#19#20#21#22#23#24#25#26#"
Output: "abcdefghijklmnopqrstuvwxyz"

Constraints:

  • 1 <= s.length <= 1000
  • s[i] only contains digits letters (‘0’-‘9’) and ‘#’ letter.
  • s will be valid string such that mapping is always possible.

Solution in python:

class Solution:
    def freqAlphabets(self, s: str) -> str:
        alist = ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10#', '11#', 
                '1']
        i = len(s)-1
        result = []
        while i >= 0:
            if s[i] != '#':
                result.append(chr(int(s[i])+96))
                i -= 1
            else:
                result.append(chr(int(s[i-2:i])+96))
                i -= 3
        return ''.join(result[::-1])
最后修改日期: 2021年3月9日

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