HJ31 单词倒排

#include<string>
#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
 
void split(const string &str, vector<string> &vec){
    int begin = 0, len = 0;
    bool renew_begin = true;

    for(int i = 0; i <str.length(); i++){
        if((str[i] >= 'a' && str[i] <= 'z') || (str[i] >= 'A' && str[i] <= 'Z')){
            len++;
            if(renew_begin){
                begin = i;
                renew_begin = false;
  
            }
            if(i == str.length()-1){
                string temp = str.substr(begin,len);
                vec.push_back(temp);
                break;
            }
        }
        else{
            if(len>=1){
                string temp = str.substr(begin,len);
                vec.push_back(temp);
                renew_begin = true;
                len = 0;
            }
        }
         
    }
} 

int main()
{
    string str;
    getline(cin,str);
    vector<string> vec;
    
    split(str, vec);
    reverse(vec.begin(), vec.end());

    for(auto it = vec.begin(); it != vec.end(); it++)
    {
        if(it<vec.end()-1)
            cout<<*it<<" ";
        else
            cout<<*it;
    }
    return 0;
}