我是RE小专家，求条

#include<bits/stdc++.h>
using namespace std;

int zh(string a){
    int as = a.size();
    int ans;
    for(int i = 0;i < as;i ++){
        ans += int(a[i] + ans * 10);
    }
    return ans;
}

string zhh(int a){
    string aa;
    while(a){
        int x = a % 10;
        aa += char(x + '0');
        a /= 10;
    }
    return aa;
}

int zjsy(string aa,string bb,char c){
    int a,b;
    a = zh(aa);
    b = zh(bb);
    if(c == '+')return a + b;
    if(c == '-')return a - b;
    if(c == '*')return a * b;
    else return a / b;
}

int main(){
    string a;
    stack <string> s;
    cin >> a;
    int as = a.size();
    string aaa;
    for(int i = 0;i < as;i ++){
        if(a[i] - '0' >= 0 && a[i] - '0' <= 9)aaa += a[i];
        else if(a[i] == '.'){
            s.push(aaa);
            aaa = "";
        }
        else {

            string x,y;
            x = s.top();
            s.pop();
            y = s.top();
            s.pop();
            s.push(zhh(zjsy(x,y,a[i])));
            if(a[i] == '@'){cout << zjsy(x,y,a[i]);return 0;}

        }

    }
    return 0;
}

全RE，写的什么东西我自己都看不懂了