434. Number of Segments in a String-字符串中的单词数

You are given a string s, return the number of segments in the string. 

A segment is defined to be a contiguous sequence of non-space characters.

Example 1:
Input: s = "Hello, my name is John"
Output: 5
Explanation: The five segments are ["Hello,", "my", "name", "is", "John"]

Example 2:
Input: s = "Hello"
Output: 1

Example 3:
Input: s = "love live! mu’sic forever"
Output: 4

Example 4:
Input: s = ""
Output: 0

Constraints:

• 0 <= s.length <= 300
• s consists of lower-case and upper-case English letters, digits or one of the following characters "!@#$%^&*()_+-=’,.:".
• The only space character in s is ‘ ‘.

Solution in python:

class Solution:
    def countSegments(self, s: str) -> int:
        t = s + " "
        k = len(s)
        i = 0
        count = 0
        while i < k:
            if s[i] == ' ':
                i += 1
            else:
                while i < k and s[i] != ' ':
                    i += 1
                count += 1
        return count