Reverse Words in a String III

Java

class Solution {
		public String reverseWords(String s) {
			StringBuilder result = new StringBuilder();
			StringBuilder word = new StringBuilder();
			int n = s.length();
			for (int i = 0; i < n; i++) {
				if (s.charAt(i) != ' ') {
					word.append(s.charAt(i));
				} else {
					result.append(word.reverse()); 	//遇到空格后，先reverse单词
					result.append(" ");		//然后加空格
					word.setLength(0);  		//这个是清空/更新的意思？还是新建了一个容器？
				}
			}
			result.append(word.reverse());
			return result.toString();
		}
}

Time Complexity : O(n); iterate the string 
Space Complexity : O(n); new StringBuilder