Write a C program that prompts the user to enter a hexadecim

Write a C++ program that prompts the user to enter a hexadecimal digit or an integer between 0-15 and display its corresponding decimal number or hex decimal number. The program must first ask the user to choose what kind of conversion and then ask the user to enter a number to convert. ( Include comments )

Solution

// C++ code
#include <iostream>
#include <fstream>
#include <cctype>
#include <cstring>
#include <stdlib.h> /* srand, rand */
#include <iomanip>
#include <limits.h>
#include <cmath>
#include <algorithm>
#include <vector>
#include <stack>

using namespace std;

int getvalue(char ch)
{
if (ch >= \'0\' && ch <= \'9\')
return (int)ch - \'0\';
else
return (int)ch - \'A\' + 10;
}

void toHexaDecimal(int decimalNumber)
{
if (decimalNumber == 0)
return;

int remainder = decimalNumber % 16;
decimalNumber /= 16;
toHexaDecimal(decimalNumber);

  
if (remainder > 9)
cout << (char)(remainder - 10 + \'A\');
else
cout << remainder;
}

int toDecimal(string s)
{
int l = s.length();
int power = 1;
int decimalNumber = 0;

for (int i = l - 1; i >= 0; i--)
{

if (getvalue(s[i]) >= 16)
{
cout << \"Invalid Number\ \";
return -1;
}

decimalNumber += getvalue(s[i]) * power;
power = power * 16;
}

return decimalNumber;
}

int main()
{
int choice;
string s;
int number;

while(true)
{
cout << \"\ 1. Hex to Decimal\ 2. Decimal to Hex\ 3. Quit\ Enter your choice: \";
cin >> choice;

if(choice == 1)
{
cout << \"Enter Hex: \";
cin >> s;
cout << \"Decimal: \" << toDecimal(s) << endl;
}

else if(choice == 2)
{
cout << \"Enter decimal: \";
cin >> number;

cout << \"Hex: \";
toHexaDecimal(number);
cout << endl;

}
else if(choice == 3)
break;
else
cout << \"Invalid Input\ \";
}

return 0;
}

/*
output:

1. Hex to Decimal
2. Decimal to Hex
3. Quit
Enter your choice: 1
Enter Hex: 11A
Decimal: 282

1. Hex to Decimal
2. Decimal to Hex
3. Quit
Enter your choice: 2
Enter decimal: 282
Hex: 11A

1. Hex to Decimal
2. Decimal to Hex
3. Quit
Enter your choice: 3

*/