Convert Hexadecimal to Octal Program in C++

C++ program to Convert Hexadecimal to Octal

To convert Hexadecimal number to Octal number in C++ programming, We have to ask to the user to enter the hexadecimal number to convert it into Decimal number to display the equivalent value in Octal format on screen.
At first convert each digit in hexadecimal to four bit binary number and than convert binary to octal. For example convert (A4)16 to octal.

Input Hexadecimal Number : 2C
Euivalent Octal Number : 54

Input Hexadecimal Number : 1E
Euivalent Octal Number : 36

Input Hexadecimal Number : D
Euivalent Octal Number : 15

#include<iostream.h>
#include<conio.h>
#include<stdio.h>
#include<math.h>

void main ()
{
 
    long i,y,hexa[20],binary[20],rem,octal=0,z=0,temp=1,w=0;
    char input[20];
	clrscr();
    cout<<"Enter any Hexadecimal Number: ";
    gets(input);
    for(y=0;input[y]!='\0';y++);
    for(i=y-1;i>=0;i--)
    {
        if(input[i]>='A'&&input[i]<='F')
            hexa[i]=input[i]-55;
        else if(input[i]>='a')
            hexa[i]=input[i]-87;
        else
            hexa[i]=input[i]-48;
        for(int y=0;y<4;y++)
        {
            rem=hexa[i]%2;
            hexa[i]/=2;
            binary[z++]=rem;
        }
    }
    for(i=0;i<z;)
    {
        for(y=0;y<3;y++)
        {
            if(i>=0)
             octal+=binary[i++]*pow(2,y);
        }
       w+=octal*temp;
       octal=0;
       temp*=10;
    }
    cout<<"Equivalent Octal Number is: "<<w;

   getch();
}

Enter any Hexadecimal Number: 1B
Equivalent Decimal Value is: 33