算法1

顺序存入（vector)每一个单词，逆序输出即可

C++ 代码

class Solution {
public:
    string reverseWords(string s) {
        vector<string> result;
        string temp = "";
        for(int i=0;i<s.size();i++){
            if(s[i]!=' '){
                temp += s[i];
            }else{
                result.push_back(temp);
                temp = "";
            }
            if(i==s.size()-1){
                result.push_back(temp);
            }
        }
        if(result.size()==0){
            return "";
        }
        string res = result[result.size()-1];
        for(int i=result.size()-2;i>=0;i--){
            res += " " + result[i];
        }
        return res;
    }
};