Python 刷Leetcode题库，顺带学英语单词（39）

For example:
1 -> A
2 -> B
3 -> C
...
26 -> Z
27 -> AA
28 -> AB
...
Examples:
Input: 1
Output: "A"
Input: 28
Output: "AB"
Input: 701
Output: "ZY"

>>> def num2chr(n):
  ret = ''
  while n//26:
    n,m = divmod(n-1,26)
    ret = chr(m+65) + ret
  if n:ret = chr(n+64) + ret
  return ret
>>> num2chr(1)
'A'
>>> num2chr(28)
'AB'
>>> num2chr(701)
'ZY'
>>> num2chr(703)
'AAA'
>>> num2chr(1502)
'BET'
>>> num2chr(16384)
'XFD'
>>> num2chr(17860)
'ZJX'
>>> 

A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28
...
Examples:
Input: "A"
Output: 1
Input: "AB"
Output: 28
Input: "ZY"
Output: 701

>>> def chr2num(s):
  return sum([(ord(n)-64)*26**i for i,n in enumerate(list(s)[::-1])])
>>> chr2num('A')
1
>>> chr2num('AB')
28
>>> chr2num('ZY')
701
>>> chr2num('AAA')
703
>>> chr2num('XFD')
16384
>>> 
>>> chr2num('YRH')
17376