codeforces水题100道 第二十五题 Codeforces Round #197 A. Helpful Maths (Div. 2) (strings)

#include <iostream>
#include <string>
using namespace std;
int cnt[3];
string s, ans = "";
int main()
{
    cin >> s;
    int len = s.length();
    for (int i = 0; i < len; i += 2)
        cnt[ s[i] - ‘1‘ ] ++;
    for (int i = 0; i < 3; i ++)
    {
        while (cnt[i] --)
        {
            char c = ‘1‘ + i;
            ans += "+";
            ans += c;
        }
    }
    cout << ans.substr(1);
    return 0;
}