设计一个简单的SmallInt类，用来表示从-128到127之间的整数。类的唯一的数据成员val存放一个-128到127（包含-128和127这两个数）之间的整数。 【注意】构造SmallInt类对象时，当给定整数不在指定范围时，需要做相应正规化处理。所谓正规化处理就是当成员数据val的值大于127时，就要减去256，当val的值小于-128时，就需要加上256，直到满足要求为止。 main函数已给定，提交时只需要提交main函数外的代码部分。 #include<iostream> using namespace std; //你提交的代码在这里 int main() { SmallInt s1,s2,s3; cin>>s1>>s2; s3=s1+s2; cout<<s1<<" + "<<s2<<" = "<<s3<<endl; s3=s1-s2; cout<<s1<<" - "<<s2<<" = "<<s3<<endl; s3=s1*s2; cout<<s1<<" * "<<s2<<" = "<<s3<<endl; s3=s1/s2; cout<<s1<<" / "<<s2<<" = "<<s3<<endl; return 0; }输入1 2输出1 + 2 = 3 1 - 2 = -1 1 * 2 = 2 1 / 2 = 0请补充完整代码

#include<iostream>
using namespace std;

class SmallInt{
    private:
        int val;
        void normalize(); // 辅助函数，用于正规化处理
    public:
        SmallInt(int v = 0): val(v){ normalize(); } // 构造函数
        friend istream& operator>>(istream& in, SmallInt& s); // 输入操作符重载
        friend ostream& operator<<(ostream& out, const SmallInt& s); // 输出操作符重载
        friend SmallInt operator+(const SmallInt& s1, const SmallInt& s2); // 加法操作符重载
        friend SmallInt operator-(const SmallInt& s1, const SmallInt& s2); // 减法操作符重载
        friend SmallInt operator*(const SmallInt& s1, const SmallInt& s2); // 乘法操作符重载
        friend SmallInt operator/(const SmallInt& s1, const SmallInt& s2); // 除法操作符重载
};

void SmallInt::normalize(){
    while(val < -128) val += 256;
    while(val > 127) val -= 256;
}

istream& operator>>(istream& in, SmallInt& s){
    in >> s.val;
    s.normalize();
    return in;
}

ostream& operator<<(ostream& out, const SmallInt& s){
    out << s.val;
    return out;
}

SmallInt operator+(const SmallInt& s1, const SmallInt& s2){
    SmallInt res(s1.val + s2.val);
    return res;
}

SmallInt operator-(const SmallInt& s1, const SmallInt& s2){
    SmallInt res(s1.val - s2.val);
    return res;
}

SmallInt operator*(const SmallInt& s1, const SmallInt& s2){
    SmallInt res(s1.val * s2.val);
    return res;
}

SmallInt operator/(const SmallInt& s1, const SmallInt& s2){
    SmallInt res(s1.val / s2.val);
    return res;
}

int main(){
    SmallInt s1, s2, s3;
    cin >> s1 >> s2;
    s3 = s1 + s2;
    cout << s1 << " + " << s2 << " = " << s3 << endl;
    s3 = s1 - s2;
    cout << s1 << " - " << s2 << " = " << s3 << endl;
    s3 = s1 * s2;
    cout << s1 << " * " << s2 << " = " << s3 << endl;
    s3 = s1 / s2;
    cout << s1 << " / " << s2 << " = " << s3 << endl;
    return 0;
}