LeetCode58----Length of Last Word

LeetCode敲的第一题，小菜鸟一只，纪念一下~~

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

.

class Solution {
public:
int lengthOfLastWord(string s) {
const char *p=s.c_str();
if(*p=='\0')<span style="white-space:pre">	</span>//判断字符串是否为空
{
return 0;
}
int num=0;
while(*p!='\0')<span style="white-space:pre">		</span>//判断是否为字符串尾
{
if(*p!=' ')<span style="white-space:pre">		</span>//不是空格时计数
{
num++;
p++;
}
else
{
if(*(++p)!='\0'&&*p!=' ')<span style="white-space:pre">	</span>//空格时，判断下一字符是否为串尾，并是否为连续空格，
num=0;<span style="white-space:pre">		</span>//不是串尾&&不是空格，表明为字符，重新计数；否则，进行新一轮判断

}

}
return num;

}
};