[LeetCode]58. Length of Last Word

Easy

Given a string s consists of upper/low
a8e6
er-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.

5ms:

public int lengthOfLastWord(String s) {
int i=0,j=0;
while(j<s.length()){
if(s.charAt(s.length()-1-j)==' ')
j++;
else
break;
}
while(i+j<s.length()){
if(s.charAt(s.length()-1-i-j)==' ')
return i;
i++;
}
return i;
}

精简：

public int lengthOfLastWord(String s) {
int len = s.length() - 1;
while(len > 0 && s.charAt(len) == ' ') len--;
int ans = 0;
for (int i = len; i >= 0; --i ){
if (s.charAt(i) == ' ') break;
ans++;
}
return ans;
}