Question

Write a C++ program that asks the user to input a decimal integer (i) and an integer radix from 2 to 16 (r) and outputs the value of iin radix r(base r). (HINT: use repeated division by base r)

NOTE: show output screenshot

Answer 1

CODE

#include <iostream>

#include <cstring>

using namespace std;

// To return char for a value. For example '2'

// is returned for 2. 'A' is returned for 10. 'B'

// for 11

char reVal(int num)

{

  if (num >= 0 && num <= 9)

    return (char)(num + '0');

  else

    return (char)(num - 10 + 'A');

}

// Utility function to reverse a string

void strev(char *str)

{

  int len = strlen(str);

  int i;

  for (i = 0; i < len/2; i++)

  {

    char temp = str[i];

    str[i] = str[len-i-1];

    str[len-i-1] = temp;

  }

}

// Function to convert a given decimal number

// to a base 'base' and

char* fromDeci(char res[], int base, int inputNum)

{

  int index = 0; // Initialize index of result

  // Convert input number is given base by repeatedly

  // dividing it by base and taking remainder

  while (inputNum > 0)

  {

    res[index++] = reVal(inputNum % base);

    inputNum /= base;

  }

  res[index] = '\0';

  // Reverse the result

  strev(res);

  return res;

}

// Driver program

int main()

{

  int inputNum, base;

cout << "Enter a decimal number: ";

cin >> inputNum;

cout << "Enter a base between 2 and 16: ";

cin >> base;

  char res[100];

  printf("Equivalent of %d in base %d is "

    " %s\n", inputNum, base, fromDeci(res, base, inputNum));

  return 0;

}

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