leetcode -- Length of Last Word

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

.

[解题思路]

从最后往前扫描。处理如下三种模式：(*表示若干个空格)
1. "*"
2. "*word"
3. "*word*"
4. "word*"

public int lengthOfLastWord(String s) {
// Start typing your Java solution below
// DO NOT write main() function
if(s.length() == 0)
return 0;

String[] strs = s.split(" ");
for(int i = strs.length - 1; i >= 0; i++){
if(isWord(strs[i])){
return strs[i].length();
}
}
return 0;
}

public boolean isWord(String s){
if(s.length() == 0)
return false;

for(int i = 0; i < s.length(); i++){
if((s.charAt(i) < 'a' && s.charAt(i) > 'z') ||
(s.charAt(i) < 'A' && s.charAt(i) > 'Z')){
return false;
}
}

return true;
}
}