LeetCode 58. Length of Last Word(最後一個單詞的長度)
阿新 • • 發佈:2019-02-09
Given a string s consists of upper/lower-case alphabets and empty space characters '
'
, return the length of last word in the string.
If the last word does not exist, return 0.
Note: A word is defined as a character sequence consists of non-space characters only.
For example,
Given s = "Hello World"
return
5
.
方法:兩次尋找空格。
public class Solution { public int lengthOfLastWord(String s) { int to = s.length()-1; while (to>=0 && s.charAt(to) == ' ') to --; if (to<0) return 0; int from = to - 1; while (from>=0 && s.charAt(from) != ' ') from --; return to-from; } }
另一種實現:
public class Solution { public int lengthOfLastWord(String s) { int stop = s.length(); for(int i = s.length() - 1; i >= 0; i--) { if (s.charAt(i) != ' ') break; stop = i; } int start = stop; for(int i = start; i > 0; i--) { if (s.charAt(i - 1) == ' ') break; start = i - 1; } return stop - start; } }