10进制转换为16进制 c++

#include <iostream>
#include <string>
using namespace std;

class Trans10
{
private:
    string str;
    string transtime(long long t)
    {
        string temp="";
        long long t1 = t/16;
        long long t2 = t%16;
        char c;
        while(t1>0)
        {
            if(t2<10)
            {
                c=t2+'0';
                temp.insert(0,1,c);
            }
            else
            {
                c=('A'+(t2-10));
                temp.insert(0,1,c);
            }
            t2=t1%16;
            t1/=16;
        }
        if(t2<10)
        {
            c=t2+'0';
            temp.insert(0,1,c);
        }
        else if(t2>10)
        {
            c=('A'+(t2-10));
            temp.insert(0,1,c);
        }
        temp.insert(0,"0x");
        return temp;
    }
public:
    Trans10(string& a):str(a){}
    string trans(){
        long long t = 0;
        for(int i=0;i<str.size();++i)
            t = t*10 + str[i]-'0';
        return transtime(t);
    }
};

int main()
{
    string teststring;
    cin>>teststring;
    
    Trans10 test(teststring);
    cout<<test.trans()<<endl;
}

结果：