Question

Computer Architecture and Organization(c++)

Write a C++ program that prompts the user to enter a hexadecimal value, multiplies it by ten, then displays the result in hexadecimal. Your main function should

a) declare a char array

b) call the readLn function to read from the keyboard,

c) call a function to convert the input text string to an int,

d) multiply the int by ten,

e) call a function to convert the int to its corresponding hexadecimal text string,

f) call writeStr to display the resulting hexadecimal text string.

the hint i was given was:

#include <iostream>

#include <cstring>

using namespace std;

char decToHex(int dec)

{

char hex;

switch (dec)

{

case 0: hex = '0';

break;

case 1: hex = '1';

break;

case 2: hex = '2';

break;

case 3: hex = '3';

break;

case 4: hex = '4';

break;

case 5: hex = '5';

break;

//

//

case 10: hex = 'A';

break;

case 11: hex = 'B';

break;

//

//

case 15: hex = 'F';

}

return hex;

}

void reverseArray(char arr[])

{

int j = strlen(arr) - 1;

int i = 0;

while ( i < j )

{

char temp = arr[i];

arr[i] = arr[j];

arr[j] = temp;

i++;

j--;

}

}

void intToHex(int intVal, char hexArr[])

{

int remainder;

int i = 0;

while (intVal > 0)

{

remainder = intVal % 16;

hexArr[i] = decToHex(remainder);

intVal = intVal / 16;

i++;

}

reverseArray(hexArr);

}

int hexToDec(char hex)

{

int dec;

switch (hex)

{

case '0': dec = 0;

break;

case '1': dec = 1;

break;

case '2': dec = 2;

break;

case '3': dec = 3;

break;

case '4': dec = 4;

break;

case '5': dec = 5;

break;

//

//

case 'A':

case 'a': dec = 10;

break;

case 'B':

case 'b': dec = 11;

break;

//

//

case 'F':

case 'f': dec = 15;

}

return dec;

}

int main()

{

char hexaInput[17];

char hexaResult[17] = { '\0' };

cout << "Enter hexadecimal: ";

cin >> hexaInput;

cout << "You typed: " << hexaInput << "\n";

int count = strlen(hexaInput);

double powerVal = 0.0;

int decValue = 0;

for (int i = count - 1; i >= 0 ; i--)

{

cout << hexToDec(hexaInput[i]) << "\n";

decValue += hexToDec(hexaInput[i]) * pow(16, powerVal);

powerVal++;

}

cout << "Decimal value is " << decValue << "\n";

intToHex(decValue*10, hexaResult);

cout << "For decimal " << decValue*10 << " Hexadecimal is: " << hexaResult <<

endl;

return 0;

}

Answer 1

#include <iostream>
#include<cmath>
#include <cstring>
#include<ctype.h>

using namespace std;

void reverseArray(char *hexArr,int start,int end)
{
   while (start < end)
{
char temp = hexArr[start];
hexArr[start] = hexArr[end];
hexArr[end] = temp;
start++;
end--;
}
}

void decToHex(int intVal, char hexArr[])

{

   int remainder;
   int i = 0;
   while (intVal != 0)
{
remainder = intVal % 16;
if (remainder < 10)
hexArr[i++] = remainder + 48; // numbers in hex
else
hexArr[i++] = remainder + 55; // 10 +55 = 65 = A
intVal = intVal / 16;
   }
  
reverseArray(hexArr,0,i-1);

}

int hexToDec(char hex)

{

   char ch = toupper(hex);
   if (ch >= 'A' && ch <= 'F')
       return 10 + ch - 'A';
   else
       return ch - '0';

}

int main()

{

char hexaInput[17];

char hexaResult[17] = { '\0' };

cout << "Enter hexadecimal: ";

cin >> hexaInput;

cout << "You typed: " << hexaInput << "\n";

int count = strlen(hexaInput);

int powerVal = 0;

int decValue = 0;

for (int i = count - 1; i >= 0 ; i--)

{   
   decValue += hexToDec(hexaInput[i]) * pow(16, powerVal);
  
   powerVal++;

}

cout << "Decimal value is " << decValue << "\n";

decToHex(decValue*10, hexaResult);

cout << "For decimal " << decValue*10 << " Hexadecimal is: " << hexaResult << endl;

return 0;

}

/* OUTPUT */