Reverse Words in a String

Reverse Words in a String

翻转string里的单词顺序。

Given an input string, reverse the string word by word.

For example,
Given s = "the sky is blue",
return "blue is sky the".

Solution:

    public String reverseWords(String s) {
        if(s == null || s.length() <= 1) {
            return s;
        }
        String[] array = s.split(" ");
        StringBuilder sb = new StringBuilder();
        for (int i = array.length - 1; i >= 0; i--) {
            sb.append(array[i]);
            sb.append(" ");
        }
        if(sb.length() > 0) {
            sb.deleteCharAt(sb.length() - 1);
        }
        return sb.toString();
    }

思路：

将单词从string分割出来，逆序重组即可。注意StringBuilder是否会为空。

例如 string = ”    “；

StringBuilder 是非同步的， StringBuffer 是同步的，线程共享的Buffer。