434. 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

题目含义：计算字符串中的非空子串的个数。
思路：找到每个单词的开头字母，就算作一个单词

    public int countSegments(String s) {
        int res=0;
        for(int i=0; i<s.length(); i++)
            if(s.charAt(i)!=' ' && (i==0 || s.charAt(i-1)==' '))
                res++;
        return res;        
    }