题解 | #图片整理#

#include <iostream>
#include <set>
using namespace std;

int main(int argc, char* argv[]){
    multiset<char> dic;
    char c;
    while(cin >> c){
        dic.insert(c);
    }
    for(auto c : dic){
        cout << c;
    }
    cout << endl;
    
    return 0;
}