Question

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

Analyze

在给定的一段字符串中，判断出来里面的单词个数，我们只需要设置一个word开始的标志位word_flag，刚刚单词开始的时候将其设置为1，当出现空格的时候，将其变成0，这样我们就可以记录单词的格式，如果到最后一个字母的话，那就将其作为单词的结尾，给单词数量加1.

Solution

class Solution {
public:
    int countSegments(string s) {
      int len = s.length(), count = 0, word_flag = 0;

      for(int i = 0; i < len; ++i) {
        if(s[i] != ' ' && word_flag == 0) word_flag = 1;
        if( (s[i] == ' ' || i == len-1 ) && word_flag == 1) {
          word_flag = 0;
          ++count;
        }
      }
      return count;
    }
};