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"

int lengthOfLastWord(char *s) {
    
    int len,k,i;
    len=strlen(s);
    k=0;
    i=len-1;
    while(s[i]==' ') i--;
    for(;i>=0;i--)
    {
        if(s[i]!=' ')
        {
            k++;
        }
        else
        {
            break;
        }
    }
    return k;
}