Given an input string, reverse the string word by word.
For example,
Given s = "the sky is blue
",
return "blue is sky the
".
Update (2015-02-12):
For C programmers: Try to solve it in-place in O(1) space.
Clarification:
- What constitutes a word?
A sequence of non-space characters constitutes a word. - Could the input string contain leading or trailing spaces?
Yes. However, your reversed string should not contain leading or trailing spaces. - How about multiple spaces between two words?
Reduce them to a single space in the reversed string.
题目大意:给一个String,以空格分隔,以单词为单位反转这个String。
解题思路:用java自带的split,拆成数组,然后组合。。。
public String reverseWords(String s) { if (s == null || s.length() == 0) { return s; } String[] res = s.split(" "); if (res.length == 0) { return ""; } StringBuilder sb = new StringBuilder(); for (int i = res.length - 1; i >= 0; i--) { if ("".equals(res[i])) { continue; } sb.append(res[i]).append(" "); } return sb.substring(0, sb.length() - 1); }