【LeetCode】 Length Of LastWord

int LengthOfLastWord(string str)
{
int end = str.length() - 1;
int len = 0;
if (str[end] == ' ')
return 0;
while (str[end] != ' ')
{
if (end == -1)
{
break;
}
else
{
len++;
end--;
}
}
return len;
}
int LengthOfLastWord2(const char *input)
{
int len = 0;
while (*input)
{
if (*input++ != ' ')
len++;
else if (*input && *input!=' ')
{
len = 0;
}
}
return len;
}