【leetcode刷题笔记】Reverse Words in a String

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

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

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题解：用栈就行了

代码：

 1 class Solution {
 2 public:
 3     void reverseWords(string &s) {
 4         stack<string>st;
 5         string temp = "";
 6 
 7         for(int i = 0;i <= s.length();i++){
 8             if(i == s.length())
 9             {
10                 st.push(temp);
11             }
12             else if(s[i] != ' '){
13                 temp += s[i];
14             }
15             else
16             {
17                 if(temp != ""){
18                     st.push(temp);
19                     temp = "";
20                 }
21             }
22         }
23         s = "";
24         while(!st.empty()){
25             if(st.top() != " ")
26                 s += st.top();
27             st.pop();
28             if(!st.empty() && s != ""){
29                 s += " ";
30             }
31         }
32     }
33 };