186. Reverse Words in a String II
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?
可以先把每一个单词reverse，然后整个list reverse。
public void ReverseWords(char[] s) { if(s.Length == 0) return ; int start = 0; int end = 0; int i = 0; while(end <= s.Length) { if(end ==s.Length || s[end] == ' ') { ReverseWord(s,start,end-1); start = ++end; } else end++; } ReverseWord(s,0,s.Length-1); } public void ReverseWord(char[] s, int start, int end) { while(start<end) { char temp = s[start]; s[start++] = s[end]; s[end--] = temp; } }