408. Valid Word Abbreviation

Given anon-emptystringsand an abbreviationabbr, return whether the string matches with the given abbreviation.
A string such as"word"contains only the following valid abbreviations:
["word", "1ord", "w1rd", "wo1d", "wor1", "2rd", "w2d", "wo2", "1o1d", "1or1", "w1r1", "1o2", "2r1", "3d", "w3", "4"]
Notice that only the above abbreviations are valid abbreviations of the string"word". Any other string is not a valid abbreviation of"word".
Note:Assumescontains only lowercase letters andabbrcontains only lowercase letters and
digits.
Example 1: Givens= "internationalization",abbr= "i12iz4n":Return true.

这么一道简单的小题， 抠嗤了一个多小时， 

两点老生常谈的问题：
1： 命名规则要好好些， 不要用i，j 乱指一通， 很容易颠倒。
2： 考虑问题， 先正向思维， 这样逻辑不容易出错。发现正向有弊端，再考虑逆向。