Example:
​
Input: "Hello, my name is John"
Output: 5

class Solution {
    public:
    int countSegments(string s) {
        int res=0;
        bool ischar=false;
        if(s.empty()) return res;
        if(s.size()==1) return s[0]!=' ';
​
        for(int i=1;i<s.length();i++)
            if((s[i]==' ') && (s[i-1] !=' '))
            {
                res++;
                //cout<<" "<< i<< res<<" "<<s[i]<<" "<<s[i-1]<<endl;
                ischar=false;
            }
            else if(s[i]!=' ')
                ischar=true;
​
        return res+ischar;
    }
};