Leetcode 58. Length of Last Word

58. Length of Last Word

• Total Accepted: 103816
• Total Submissions: 345263
• Difficulty: Easy

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：由后向前遍历，先去掉末尾的空格，然后截取最后一个word。

 

代码：

class Solution {
public:
    int lengthOfLastWord(string s) {
        int i=s.size()-1,j;
        while(i>=0&&s[i]==' ') i--;
        j=i;
        while(i>=0&&s[i]!=' ') i--;
        return j-i;
    }
};