c++ 手动分割字符串 or stringstream来处理

//// cin.get == '\n'
#include <iostream>
#include <sstream>
#include <algorithm>

using namespace std;

int main(){

    string tmp;
    vector<string> res;
    while(cin >> tmp)
    {
        //双指针法分割字符串
        for(int i = 0;i < tmp.size(); i++)
        {
            int j = i;
            while(tmp[j] != ',' && j < tmp.size()) j++;
            res.push_back(tmp.substr(i,j - i));
            i = j;
        }

        if(cin.get() == '\n')
        {
            sort(res.begin(),res.end());
            for(int i = 0 ; i < res.size() - 1; i++)
                cout << res[i] <<  ',';
            cout << res[res.size() - 1] <<endl;
            res.clear();
        }
    }
    return 0;
}

//// getline() + stringstream
#include <iostream>
#include <sstream>
#include <algorithm>

using namespace std;

int main(){
    string str;
    while (getline(cin, str)){
        // str - > ss - > s
        stringstream ss;
        ss << str;
        string s; 
        vector<string> res;
        //以逗号对ss进行分割
        while (getline(ss, s, ','))
            res.push_back(s);
        //排序
        sort(res.begin(), res.end()); 
        //输出
        for(int i = 0 ; i < res.size() - 1; i++)
            cout << res[i] <<  ',';
        cout << res[res.size() - 1] <<endl;
    }
    return 0;
}