LeetCode习题笔记——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.

Example:

Input: "Hello World"
Output: 5

这个题就很简单了，既然说是要最后一个单词的长度，就从后面开始遍历，从结尾第一个不为空格字符串开始计算，然后遇到空格结果并输出结果即可。

class Solution {
public:
    int lengthOfLastWord(string s) {
        int end = s.size() - 1;
        int res = 0;
        while (end >= 0 && s[end] == ' ')
            --end;
        while (end >= 0 && s[end] != ' ') { //注意要>=0,保证遍历到每一个字符
            end--;
            res++;
        }
        return res;
    }
};