Given an input string, reverse the string word by word.
For example,
Given s = "the sky is blue",
return "blue is sky the".
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.
提交了好多遍，终于成功了，使用了sstream来分割字符串，使用栈来存放分割之后的字符串，然后出栈就是逆序了。。
C++实现代码：
#include<iostream> #include<string> #include<sstream> #include<stack> using namespace std; class Solution { public: void reverseWords(string &s) { if(s.empty()) return; stringstream ss(s); s.clear(); stack<string> st; string tmp; while(ss>>tmp) { st.push(tmp); } while(!st.empty()) { tmp=st.top(); st.pop(); if(!st.empty()) s+=tmp+' '; else s+=tmp; } } }; int main() { Solution s; string ss=" the sky is blue "; cout<<ss.length()<<endl; cout<<ss<<endl; s.reverseWords(ss); cout<<ss.length()<<endl; cout<<ss<<endl; }
运行结果：
运行结果：
