[LeetCode OJ]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

简单的判断char，从后往前找，返回长度。

class Solution {
public:
bool isChar(char a) {
return (a >= 'a' && a <= 'z') || (a >= 'A' && a <= 'Z');
}

int lengthOfLastWord(const char *s) {
int len = strlen(s);
int begin, end;

end = len - 1;
while((end >= 0) && s[end] == ' ')
end--;

begin = end;
while((begin >= 0) && isChar(s[begin]))
begin--;

return end - begin;
}
};