Code：

#include<bits/stdc++.h>
#define int long long
#define db double
using namespace std;
signed main(){
    string s; cin >> s;
    string s1 = "";
    for(int i = 0;i < s.size();i++){
        if(s[i] == '.'){
            int t = stoi(s1),k = 0;
            while(t){
                k = k * 10 + t % 10;
                t /= 10;
            }
            s1 = "";
            cout << k << ".";
        }else if(s[i] == '/'){
            int t = stoi(s1),k = 0;
            while(t){
                k = k * 10 + t % 10;
                t /= 10;
            }
            s1 = "";
            cout << k << "/";
        }else if(s[i] == '%'){
            int t = stoi(s1),k = 0;
            while(t){
                k = k * 10 + t % 10;
                t /= 10;
            }
            cout << k << "%";
            break;
        }else s1 += s[i];
        if(i == s.size() - 1){
            int t = stoi(s1),k = 0;
            while(t){
                k = k * 10 + t % 10;
                t /= 10;
            }
            cout << k;
            break;
        }
    }
    return 0;
}

5个RE：#1#2#3#4#19