Convert a Number to Hexadecimal in C++

Suppose we have an integer; we have to devise an algorithm to convert it to hexadecimal. For negative numbers we will use the two’s complement method.

So, if the input is like 254 and -12, then the output will be fe and fffffff4 respectively.

To solve this, we will follow these steps −

• if num1 is same as 0, then −

  • return "0"

• num := num1

• s := blank string

• while num is non-zero, do −

  • temp := num mod 16

  • if temp <= 9, then −

    • s := s + temp as numeric character

  • Otherwise

    • s := s + temp as alphabet

  • num := num / 16

• reverse the array s

• return s

Example 

Let us see the following implementation to get a better understanding −

 Live Demo

#include <bits/stdc++.h> using namespace std; class Solution { public:    string toHex(int num1){       if (num1 == 0)          return "0";       u_int num = num1;       string s = "";       while (num) {          int temp = num % 16;          if (temp <= 9)             s += (48 + temp);          else             s += (87 + temp);          num = num / 16;       }       reverse(s.begin(), s.end());       return s;    } }; main(){    Solution ob;    cout << (ob.toHex(254)) << endl;    cout << (ob.toHex(-12)); }

Input

254 -12

Output

fe fffffff4