Leetcode-Length of Last Word

#Leetcode

题目描述

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.

For example,

Given s = "Hello World",

return 5.

AC代码

	class Solution {
			public:
			    bool ischar(char p)
			    {
			    	return (p >= 'a' && p <= 'z') || (p >= 'A' && p <= 'Z');
			    }
			    int lengthOfLastWord(const char *s)
			    {
				// IMPORTANT: Please reset any member data you declared, as
				// the same Solution instance will be reused for each test case.
			    	int len = strlen(s);
			    	if(len < 1)
			    		return 0;
			    	int end = len - 1;
			    	while((end >= 0) && (s[end] == ' '))
			    		end--;
			    	int begin = end;
			    	while((begin >= 0) && ischar(s[begin]))
			    		begin--;    
			    	return end - begin;
			    }
			};