Leetcode(58)题解:Length of Last Word

https://leetcode.com/problems/length-of-last-word/

题目：

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.

思路：

主要是确定最后一个单词的边界。注意特殊情况。

AC代码：

class Solution {
public:
    int lengthOfLastWord(string s) {
        int begin=-1,end=-1,j,n=s.size();
        for(j=n-1;j>=0;j--)
            if(s[j]!=' '){
                begin=j;
                break;
            }
        if(begin==-1)
            return 0;
        for(j=begin;j>=0;j--){
            if(s[j]==' '){
                end=j+1;
                break;
            }
        }
        if(end==-1)
            end=0;
        return begin-end+1;
    }
};