Question

(In c++) Write a void function that receives an unsigned integer value and displays the hex representation of value. You must use bit manipulation techniques.

Note that you must convert the hex value for each 4 bits starting at the right side. The hex value for 0 to 9 is the same digit. The hex value for 10 is A for 11 is B, for 12 id C, for 13 is D, for 14 is E and for 15 is F.

Answer 1

#include <stdio.h>

#include <iostream>

#include <string>

using namespace std;

void decimalToHexa(unsigned int dec_num)

{

               // First converting the number into binary

               int binary_num[1000];

               int i = 0;

               while (dec_num > 0)

               {

                              binary_num[i] = dec_num % 2;

                              dec_num = dec_num / 2;

                              i++;

               }

               // Second converting binary into hexadecimal format

               int k = 0;

               string hex_num = "";

               while (k < i)

               {

                              int hex = 0;

                              // getting the binary numbers as a group of 4 digits

                              for (int j = 0; j < 4; j++)

                              {

                                             if (binary_num[j + k] == 1)

                                             {

                                                            hex = hex + pow(2, j);

                                             }

                              }

                              // incrementing the value by 4 so that in next iteration, we move to next 4 digits of the binary number

                              k+=4;

                              // based on the value we decide which string to concatenate to the result hex_num

                              if (hex == 10)

                              {

                                             hex_num = hex_num + "A";

                              }

                              else if (hex == 11)

                              {

                                             hex_num = hex_num + "B";

                              }

                              else if (hex == 12)

                              {

                                             hex_num = hex_num + "C";

                              }

                              else if (hex == 13)

                              {

                                             hex_num = hex_num + "D";

                              }

                              else if (hex == 14)

                              {

                                             hex_num = hex_num + "E";

                              }

                              else if (hex == 15)

                              {

                                             hex_num = hex_num + "F";

                              }

                              else

                              {

                                             hex_num = hex_num + to_string(hex);

                              }

               }

               // we got the hex_num in reverse order so, reversing the entire string to get the actual result

               reverse(hex_num.begin(), hex_num.end());

               cout << hex_num << endl;

}

int main()

{

               // testing of the method

               decimalToHexa(10); // A

               decimalToHexa(16); // 10

               decimalToHexa(456); // 1C8

               decimalToHexa(1024); // 400

               decimalToHexa(8998533); // 894E85

               return 0;

}

OUTPUT