LEETCODE--Number of Segments in a String

Count the number of segments in a string, where a segment is defined to be a contiguous sequence of non-space characters.
Please note that the string does not contain any non-printable characters.
Example:
Input: “Hello, my name is John”
Output: 5
方法一：

class Solution {
public:
    int countSegments(string s) {
        int count = 0;
        for(int i = 0; i < s.length(); i++){
            int flag = 0;
            while(s[i] != ' ' && i < s.length()){
                flag = 1;
                i++;
            }
            if(flag == 1)
                count++;
        }
        return count;
    }
};

方法二：

class Solution {
public:
    int countSegments(string s) {
        int count = 0;
        s += ' ';
        for(int i = 1; i < s.length(); i++){
            if(s[i-1] != ' ' && s[i] == ' ')
                count++;
        }
        return count;
    }
};