Ｃ++：进制转换

（1）二进制转十六进制

string binary = "11010101";
string hex;
stringstream ss;
ss << std::hex << stoi(binary, nullptr, 2);
ss >> hex;
transform(hex.begin(), hex.end(), hex.begin(), ::toupper);
cout << hex <<endl;

(2）十六进制转二进制

string binary = "D5";
bitset<8> bit(stoi(binary, nullptr, 16));
cout << bit << endl;
 
输出：11010101

https://blog.csdn.net/MOU_IT/article/details/89060249