C++_n进制乘法和n进制转化成十进制函数

stack<char> pro_stack;
string multi_single(string mplier,char mplicand,int base){
    int len=mplier.size();
    int mplicand_ten=0;
    if(mplicand-48<10)
        mplicand_ten=mplicand-48;
    else
        mplicand_ten=code[mplicand-65];
    int mplier_ten=0;
    int product=0;
    char cpro=' ';
    string total_pro="";
    int carry=0;
    int real_pro=0;
    for(int i=len-1;i>=0;i--){
        if(mplier[i]-48<10)
            mplier_ten=mplier[i]-48;
        else
            mplier_ten=code[mplier[i]-65];
        real_pro=carry+mplier_ten*mplicand_ten;
        product=real_pro%base;        
        if(product>9)
            cpro=product-10+'A';
        else 
            cpro=(char)(product+48);
        pro_stack.push(cpro);
        carry=real_pro/base;
    }
    while(!pro_stack.empty()){
        total_pro.append(1,pro_stack.top());
        pro_stack.pop();
    }
    return total_pro;
}

 

//n进制转换成十进制
float transtoT(string str_n,float base){
    float num_ten=0;
    int in;
    int exp;
    for(int i=str_n.size()-1;i>=0;i--){
        if(str_n[i]-48<10)
            in=str_n[i]-48;
        else
            in=code[str_n[i]-65];
        exp=str_n.size()-1-i;
        num_ten+=in*pow(base,exp);
    }
    return num_ten;
}