408. Valid Word Abbreviation

Problem:

Given a non-empty string s and an abbreviation abbr, 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: Assume s contains only lowercase letters and abbr contains only lowercase letters and digits.

Example 1:

Given s = "internationalization", abbr = "i12iz4n":

Return true.

Example 2:

Given s = "apple", abbr = "a2e":

Return false.

Problem:

public class Solution {
    public boolean validWordAbbreviation(String word, String abbr) {
        int count = 0;
        int i = 0, j = 0;
        for (; i < abbr.length() && j < word.length(); i ++) {
            if (abbr.charAt(i) >= '0' && abbr.charAt(i) <= '9') {
                if (count == 0 && abbr.charAt(i) == '0') {
                    return false;
                }
                count = count * 10 + (abbr.charAt(i) - '0');
            } 
            else {
                if (count != 0) {
                    j = j + count;
                    count = 0;
                }
                if (j >= word.length() || abbr.charAt(i) != word.charAt(j)) {
                    return false;
                }
                j ++;
            }
        }

        return i == abbr.length() && j + count == word.length();
    }
}