Decimal to Hexadecimal using C++

Decimal Number System: It is also called base $10$ system or Denary system. It refer to any number written in decimal notation format.

Hexadecimal Number System: It is also called base $16$ system or Hex system. It refer to any number written in hexadecimal notation format. It uses sixteen different symbols $0-9$ and $A, B, C, D, E, F$ represent $10-15$.

Algorithm:

1. Divide the decimal number by $16$. Consider the division operation as an integer division.
2. Note down the remainder (in hexadecimal).
3. Divide the result again by $16$ and again consider the division as an integer division.
4. Repeat step $2$ and $3$ until result is $0$.
5. The hex value is the digit sequence of the remainders from the last to first

#include "iostream"
#include "conio.h"
#include "math.h"

using namespace std;

void dtoh(int d);
int main()
{
    int d;

    cout<< "Enter a decimal number system: ";
    cin >> d ;
    dtoh(d);
    return (0);
}

void dtoh(int d)
{
    int b,c=0,a[5],i=0;
    b=d;
    while (b>15)
    {
        a[i]=b%16;
        b=b/16;
        i++;
        c++;
    }
    a[i]=b;
    cout << "Its hexadecimal equivalent is : ";
    for (i=c;i>=0;--i)
    {
        if (a[i]==10)
        cout << "A";
        else if (a[i]==11)
        cout << "B";
        else if (a[i]==12)
        cout << "C";
        else if (a[i]==13)
        cout << "D";
        else if (a[i]==14)
        cout << "E";
        else if (a[i]==15)
        cout << "F";
        else
        cout << a[i];
    }
}

Input:    Decimal number : $12$

Output: Hexadecimal number: $C$

Input:    Decimal number : $4023$

Output: Hexadecimal number: $FB7$