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.

从后往前遍历。

需要先处理掉末尾为空格的情况，然后开始计数。

class Solution {
public:
    int lengthOfLastWord(const char *s) {
        int len = strlen(s);
        int count = 0;
        int i = len - 1;
        while(i >= 0 && s[i] == ' '){
            i--;
        }
        while(i >= 0 && s[i] != ' '){
            i--;
            count++;
        }
        return count;
    }
};