C-Program to Covert Binary to Octal

#include<stdio.h>

int main()

{

 int octalNum[]={0,1,10,11,100,101,110,111};

 long int binary,i,number,temp,octal=0,j=1;

 printf("Enter Binary number\n");

 scanf("%ld",&binary);

 temp=binary;

 while(temp!=0)

 {

  number=temp%1000;

  for(i=0;i<=7;i++)

  {

   if(octalNum[i]==number)

   {

    octal=octal+(i*j);

   }

  }

  j*=10;

  temp/=1000;

 }

 printf("Octal number for given Binary number %ld is %ld\n",binary,octal);

return 0;

}

Method II:

#include<stdio.h>

#include<math.h>

int ConvertFromBinarytoOther(int);

int ConvertFromDecimalToOther(int);

int main()

{

 int final,num,binary,decimal;

 printf("Enter Binary Number\n");

 scanf("%d",&binary);

 decimal=ConvertFromBinarytoOther(binary);//Converting binary to decimal

 final=ConvertFromDecimalToOther(decimal);//Converting decimal to octal

 //So binary to Octal

 printf("Octal number of Binary number %d is %d\n",binary,final);

return(0);

}

int ConvertFromDecimalToOther(int decimal)

{

 int temp,i,j=1,final=0;

    temp=decimal;

    while(temp!=0)

    {

      i=temp%8;

      final=final+(i*j);

      temp=temp/8;

      j=j*10;

     }

     return(final);

}

int ConvertFromBinarytoOther(int binary)

{

 int final=0,i,inc=0,temp;

    temp=binary;

    while(temp!=0)

    {

      i=temp%10;

      final=final+(i*pow(2,inc));

      temp=temp/10;

      inc++;

     }

     return(final);

}