Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.
The input string does not contain leading or trailing spaces and the words are always separated by a single space.
For example,
Given s = "the sky is blue",
return "blue is sky the".
Could you do it in-place without allocating extra space?
public class Solution { public void reverseWords(char[] s) { // Three step to reverse // 1, reverse the whole sentence reverse(s, 0, s.length - 1); // 2, reverse each word int start = 0; for (int i = 0; i < s.length; i++) { if (s[i] == ‘ ‘) { reverse(s, start, i - 1); start = i + 1; } } // 3, reverse the last word, if there is only one word this will solve the corner case reverse(s, start, s.length - 1); } public void reverse(char[] s, int start, int end) { while (start < end) { char temp = s[start]; s[start] = s[end]; s[end] = temp; start++; end--; } } }
reference：https://leetcode.com/discuss/24227/my-java-solution-with-explanation
原文：http://www.cnblogs.com/hygeia/p/5111860.html