Week 15 Length of Last Word

问题概述

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

分析

这道题主要是考虑最后是不是空格，方法是倒着找不是空格的字符并计数，如果遇到空格且计数不是0，说明最后一个单词已经被计数了，所以可以返回了。

c++代码

class Solution {
public:
    int lengthOfLastWord(string s) {
        if(s.length()==0){
			return 0;
		}
		int num = 0;
		int l = s.length();
		for(int i = l-1; i >= 0; i--){
			if(s[i] != ' '){
				num++;
			}
			if(s[i] == ' ' && num != 0) break;
		}
		return num;
    }
};