leetcode 1844. Replace All Digits with Characters(python)

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描述

You are given a 0-indexed string s that has lowercase English letters in its even indices and digits in its odd indices.

There is a function shift(c, x), where c is a character and x is a digit, that returns the xth character after c.

  • For example, shift('a', 5) = 'f' and shift('x', 0) = 'x'.

For every odd index i, you want to replace the digit s[i] with shift(s[i-1], s[i]).

Return s after replacing all digits. It is guaranteed that shift(s[i-1], s[i]) will never exceed 'z'.

Example 1:

Input: s = "a1c1e1"
Output: "abcdef"
Explanation: The digits are replaced as follows:
- s[1] -> shift('a',1) = 'b'
- s[3] -> shift('c',1) = 'd'
- s[5] -> shift('e',1) = 'f'

Example 2:

Input: s = "a1b2c3d4e"
Output: "abbdcfdhe"
Explanation: The digits are replaced as follows:
- s[1] -> shift('a',1) = 'b'
- s[3] -> shift('b',2) = 'd'
- s[5] -> shift('c',3) = 'f'
- s[7] -> shift('d',4) = 'h'

Note:

1 <= s.length <= 100
s consists only of lowercase English letters and digits.
shift(s[i-1], s[i]) <= 'z' for all odd indices i.

解析

根据题意,就是将字符串 s 中的索引为奇数时候的数字,变为前一个字符按照英文字母顺序的后面第 i 个字母,思路很简单,直接遍历字符串 s ,然后将需要变化的字母进行转换即可得到答案。

解答

 class Solution(object):
    def replaceDigits(self, s):
        """
        :type s: str
        :rtype: str
        """
        r = ""
        for i in range(len(s)):
            if i % 2 == 0:
                r += s[i]
            else:
                r += chr(ord(s[i - 1]) + int(s[i]))
        return r           	      
		

运行结果

Runtime: 24 ms, faster than 41.12% of Python online submissions for Replace All Digits with Characters.
Memory Usage: 13.5 MB, less than 44.16% of Python online submissions for Replace All Digits with Characters.

原题链接:leetcode.com/problems/re…

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