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

主要用到了 C 语言的字符数组的基本操作。

class Solution {
public:
    int lengthOfLastWord(const char *s) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int length = strlen(s);
        int len = 0;
        while(length>0 && s[length-1]==' ') {
            length--;
        }
        if(length==0)
            return 0;
        while(length>0 && s[length-1]!=' ') {
            len++;
            length--;
        }    
        return len;        
    }
};