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.
思路:算法就是:i, j兩個指針,j遇見數字,跳過,並且收集數字,然後i跳過這些數字,繼續走;注意的是:第一次不相等的時候,j不能爲0,後面j可以是0;
class Solution {
public boolean validWordAbbreviation(String word, String abbr) {
int i = 0, j = 0;
while(i < word.length() && j < abbr.length()) {
if(word.charAt(i) == abbr.charAt(j)) {
i++;
j++;
continue;
}
// 不相等的第一個,不能爲0;
if(abbr.charAt(j) <= '0' || abbr.charAt(j) > '9') {
return false;
}
int start = j;
// 不相等的後面,可以是0;
while(j < abbr.length() && '0' <= abbr.charAt(j) && abbr.charAt(j) <= '9') {
j++;
}
int num = Integer.parseInt(abbr.substring(start, j));
i += num;
}
return i == word.length() && j == abbr.length();
}
}